Shot Quality and Goal Trends
by ChicagoNativeSon on Dec 9, 2011 1:00 PM CST
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PrintAh, good to have CNS back looking up all the stats we can't be bothered to...
Ah, the FanPost section. Home sweet home. I haven't done this in a while...
There's been just an eensy weensy teeny tiny bit of talk about how bad the Hawks defense has been this year and that the Blackhawks are giving up higher quality shots. So I decided to look into the percentages of goals given up by the Hawks from different areas of the ice this season and compare that to the percentages of other teams and to last year's team.
First off, the most important ingredient in shot quality is distance. Sv% goes up dramatically as the distance of the shot increases. The second most important factor is angle. The highest percentage of goals are scored from the center of the ice. That number decreases as the shot angle increases.
So, what are the defensive keys to limiting shot quality? Limit shots from the middle of the ice, especially the low slot.
Shot Quality via Goals Allowed
I took a random sample of 11 other teams (basically I grabbed teams that played last night and made sure to include division rivals). Note that these are goal location percentages based on the entire season YTD, not simply from a single game. Here are those percentages (all data from nhl.com):
And here's how the Hawks rank:
So in reality, of these 12 teams, the Blackhawks are 1st in limiting goals from the low slot, the most dangerous location on the ice. They are also the only team below 60%.
The Hawks are also 1st in limiting total goals from the center of the ice.
The Hawks give up the most goals, by percentage, from the least dangerous areas in their zone, the higher corners.
Therefore the idea that the Hawks give up higher quality shots compared to other teams appears to be a fallacy. In fact, based on this relatively large sample, the Hawks are actually one of the best teams (if not the best) at limiting high quality shots.
2011 vs 2012
The second assumption is that this year's defense gives up higher quality shots compared to last year's team which included the likes of all-star defensemen Nick Boynton, Jassen Cullimore, Jordan Hendry, John Scott (oh shit, he's still here?), and Nick Leddy who was pulled out of class to play in the NHL. So let's compare last season to this year:
As you can see, there is a stark improvement this year in limiting goals from the slot. I didn't compare the Hawks to other teams from last season, but based on the 12 samples above, the Hawks basically sucked at limiting prime scoring chances last year. This makes Corey Crawford's stat line in 2010-11 all the more impressive. But on the flip side, it also makes his performance this year even worse.
Myth busted?
Goal Location
Sam has mentioned that Corey has a tendency to drop his glove hand this year. I haven't been paying attention to that, so I'm not sure if this is something new for him or if he also did this last year, got away with it since "the book wasn't out on him" yet, and therefore it went detected.
I don't have goal locations exclusively for Crawford, but since he started about 65% of the games last year and 75% this year, I assume the chart below has some truth to it, although it does have a lot of "noise".
There is no variance from last year to assume that Crow is giving up more goals on his glove hand side. Again there is noise, but what makes sense to me is that he was always giving up a high percentage of goals on his high glove side last year too - and that's why shooters are aiming there now. Due to his great season, we just missed it.
The only substantial difference I can see from last year to this year, is that Hawks goalies are allowing 8% more goals on their stick side. And I'm especially alarmed by the fact that 13% of all goals have gone right through the goalies. Amazing!
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way awesome.
one point of unclarity – you seem to interchange the charts as ‘goals allowed’ and ‘shots allowed’.
If the charts are ‘goals allowed’ it is pretty stark in painting the picture of the problem being solely on the netminders – as you note – with so many goals being allowed from outside the dots.
If the charts are ‘shots allowed’ it paints a slightly different picture that still jives with the eye test as the D gives up shots from above the circles (as our wingers tend to collapse into the zone).
I don’t really know what to make of the save-location charts.
Thanks for pointing that out - fixed
It is indeed “goals allowed.”
by ChicagoNativeSon on Dec 8, 2011 4:19 PM CST up reply actions
Agree.
way awesome!!!!!
My serenity is inversely proportional to my expectations.
LET’S GO YOU WHITE SOX!!!!!
LOL
“Way awesome”
This proves CRAWFORD RULEZ!!!
by ChicagoNativeSon on Dec 9, 2011 2:31 PM CST up reply actions
Yes, I had already conceded defeat.
Obviously I was wrong in my assumptions, it is nice to see data show it even clearer. I guess in the end, I was pushing to not blame Craw for all of it, and this biased me after all.
After this ass waxing I took, I’m going to have to step away from stat crap for a while, pretty sure my credibility (if I had any) is pretty much toast.
But seriously, thanks for beating it into my head and showing me I was in fact fucked up! I need that at times.
by Toews-makes-funny-faces on Dec 8, 2011 3:57 PM CST reply actions
Huh? Had nothing to do with your stats TMFF!
Obviously you’re far from the only person pinning the blame on the defense and shot quality. (and in reality, you were trying to find a happy medium) I actually ran across this data while looking for shot charts from other games besides the PHX game that laaarmer used. Since PHX was only a one game sample, I thought it best to expand on that.
Stats arguments are so different from arguments based on the eye test or opinion because often the biggest factor is whether or not the data or methodology is valid or if it’s the best approach. So discussing your findings was more about the sample size used and the subjective inferences made based on results from a very small sample. Thick skin. And obviously your credibility isn’t toast. Your stuff is awesome.
by ChicagoNativeSon on Dec 8, 2011 4:31 PM CST up reply actions
Oh, the Skin is thick
But that was a thorough Dick Slapping! lol. Did not realize how far out on the limb I had climbed, need to not let that happen again!
by Toews-makes-funny-faces on Dec 8, 2011 4:38 PM CST up reply actions
Thanks bud
Ya know, I heard a rumor from a friend of a friend that Kane has been doing some partying, if ya know what I mean.
by ChicagoNativeSon on Dec 8, 2011 10:58 PM CST up reply actions
ah those olden days of stat-filled fanposts with pretty pictures.
is it so retro that it’s now back in fashion? if so; yay! :D
but seriously, this is really interesting. the stats imply that we’re the same/better than last year. so if it’s not the team…could it be all of us, overreacting over every single thing?
…nah. as for 13% going straight through the goalies – BOTH OF THEM ARE SIEVES, TRADE EVERYONE.
SCH Narc - check yo'self before you wreck yo'self.
Bring Niemi back.
My serenity is inversely proportional to my expectations.
LET’S GO YOU WHITE SOX!!!!!
I will say this
I don’t read the GDTs, but last night I went browsing through the period threads after what I thought was a solid if unspectacular Hawks road victory against a hot team. Reading through the 3rd period thread in particular, you’d have thought the Hawks were a terrible team with no heart, grit, or whatever other undefinable word some sports fans use.
I get that it’s fun to vent and debate about sports, and this is a great medium for that. But I don’t understand how this season is the calamity that some are making it out to be. The last goal your team gives up is always going to seem like the worst one of the season. Every loss will seem like the worst loss (nevermind, Edmonton wins forever on that one). But, taking in all the numbers a whole, like CNS did here, is where the truth lies. This Hawks team is MUCH better and deeper than last year’s team, and with tons more cap space.
People can vent and emote if they want to, but it’s the reason I will probably never visit a GDT again. I like to focus on what’s actually happening, not what we feel is happening.
"I have only space enough to add: against the assault of desperate pandas nothing can stand."
-ChicoMaki (channeling Mark Twain)
by HungryHungryPanda on Dec 9, 2011 3:39 PM CST up reply actions
GDTs always were more emotional/Id- based commenting.
that fact becomes more obvious the more people there are. I feel like in the past years, when the Hawks played badly, people in the GDT just stopped commenting on the game & talked about off-topic things until something good happened again. Now, people just focus and micro-scrutinize everything, hence the GDTs seeming even more id/chaotic/PD-ish at times. Just my 2cents.
SCH Narc - check yo'self before you wreck yo'self.
Very solid point...
To be fair to “people in the GDT” we’ve been policed up about going off-topic, which was not the case in past years.
It’s a systemic thing. If the focus is on hockey, and does/can not shift away then “bad” hockey (i.e. the Hawks not currently leading the game) will cause consternation to become the standard M.O. for said GDT.
Just a theory. Not math. This cannot be proven with any formulae.
Smooth. (on rare occasions)
Maybe I'm missing something
But i’m not positive that ice position is equal to quality of chance. for example that one a few games back were this one really sucky guy (can’t remember much sorry) had a wide open net because Crow slid out of position, and the puck on his stick at the face off dot and he missed it. everyone was like OHHHH I can’t believe he missed that. And that to me is a high quality chance even though it wasn’t in the high percentage area. Additionally goals scored from the point because the defense fails to clear out traffic seems to not be taken into account. Again maybe I’m missing something and this really is some great data but I’m not sure it moves the defense into the clear and the blame to Crow.
You're looking at it on a micro, instead of macro, level
There are 4000-5000 (very roughly, 2500 SOG, 1500 missed, 750 blocked) shots directed at the net for each team in a season. These individual events statistically mean very little. And we typically fixate on them when things go badly.
Would you believe me if I told you there were as many “scoring chances” for the Islanders last night as there were for Edmonton when they scored 9? By my count, it was pretty close. But since the chances last night didn’t turn into goals, we perceive the event differently. We forget about the turnover that don’t result in goals, or the shots that get easily turned away.
Players will make turnovers, goalies will get screened, shots will get deflected, odd man rushes will occur on every team. Basically, in the end it all equals out to the point where this has almost no effect on Sv%.
One study I read, suggested only a difference of around .012 should be expected from the team that give up the lowest percentage of quality shots to the highest. So based on the area of the goals scored this year, it’s likely safe to assume that the Hawks have improved and therefore Crow’s Sv% should actually be higher than last season. (I can’t state that about Emery since he wasn’t here, plus his sample sizes from last year and this year are very small) Crow overperformed last year and he’s underperforming this year, it’s probably as simple as that.
by ChicagoNativeSon on Dec 9, 2011 8:33 AM CST up reply actions
You might want to read this one from 2010
by Toews-makes-funny-faces on Dec 9, 2011 9:21 AM CST up reply actions
It was disprove by Gabe Desjardins (Hawerchuck at Artic Ice Hockey)
the guy who runs BehindtheNet.ca.
Luck plays a bigger factor than Shot Quality.
by ChicagoNativeSon on Dec 9, 2011 10:10 AM CST up reply actions
In fact
He and Derrick Zona are offering a cash prize for anyone that can prove Shot Quality has any significant effect on Sv% over the long haul.
If you go to AIH and ask about Shot Quality, everyone there will respond “DRINK!” because it’s been disproved so many times that they banned the term.
by ChicagoNativeSon on Dec 9, 2011 10:15 AM CST up reply actions
If they say so.
If I want to take a shot at a goalie. I would prefer the mid slot to below the circle on the goal line. If that isn’t shot quality I don’t know what is. It’s bullshit CNS. There are shots that are higher quality and those shots go in more often than shots of lower quality. Shots from below the circle do not go in as often as shots from in front of the goalie.
Just because they say it’s disproved, doesn’t mean it’s disproved.
Huet is better than Niemi. They will never win the cup with Niemi. I said that nd backed it up with stats. It wasn’t true. It all happened. Sharps OT shot was much higher quality than any of Keiths.
Also, it all depends on what is determined to be a quality shot. Does a screen make a shot higher quality than an open shot. Is a shot from the half boards higher quality than a shot from the hash marks in the slot? What EXACTLY did they consider a quality shot? They also talk about goalie effects. If you shoot at Pange it’s far different than if you shoot at Roy. Also if it’s John Scott shooting rather than Stamkos.
Hold My Stones
It's not bullshit
You just can’t get out of “micro mode.” No one disputes that Shot Quality exists on an individual shot. And that’s what you are arguing. It’s just that over the long haul, it has only a minuscule effect on Sv%. And even if it did have a significant effect, Crawford’s Sv% should’ve then been much lower last year than this year. Why is that hard to accept?
Defensive errors are simply highlighted when the error results in a goal. Just like winning or losing in a freaking shootout influences how we feel about a game. The other night against PHX, if the Hawks would’ve won in the SO, many would have been raving about how such a great comeback it was. Instead, most walked away feeling “Meh. Shootouts suck.”
by ChicagoNativeSon on Dec 9, 2011 11:18 AM CST up reply actions
So you are saying that if all shots are taken fron inside the circles below the hashmarks for the entire season for every club
it will have no effect on sv%
Bullshit.
Hold My Stones
"IF" all shots are taken inside the circles...
They are not.
As you can plainly see from the charts in my post, the variance from one to team to another is not that great. The effect is minuscule.
by ChicagoNativeSon on Dec 9, 2011 11:40 AM CST up reply actions
I'm not arguing you post here, it looks nice
Where did your data come from BTN?
Also, how did the shots that went through the goalies chest not result in more deaths?
MY point is that shot quality matters, unless you are trying to prove that it doesn’t matter. For example,
“IF” all shots are taken inside the circles…
They are not.
IF 1/2 the shots were taken from this point and the other 1/2 were taken from the point, what would the results be? Your argument is they would be equal and it’s bullshit.
I will keep saying bullshit all day if I have to
Hold My Stones
No, that's not my argument
Individual Shot Quality does indeed exist, but over the long run it evens out and has little statistical effect on Sv%.
Yes, shots from in close are more dangerous from shots from the point. I even stated that in my post, right? If there was a team stupid enough to stand in the corners of the zone and just let the opposition take every single shot from the slot, then yes, Shot Quality would matter over time. But that’s not the case.
So instead of looking at the analysis and saying “Hmmm, maybe the Hawks have actually given up lower quality shots this year”, you guys are using a straw man argument, which if true, goes completely against what I believe your original point was, that “the Hawks are giving up higher quality shots.”
by ChicagoNativeSon on Dec 9, 2011 11:53 AM CST up reply actions
But like I asked TMFF, "What is your argument?"
If I agree with you that Shot Quality plays a big part in determining Sv%, IMO your argument has been greatly compromised by the actually data.
by ChicagoNativeSon on Dec 9, 2011 11:42 AM CST up reply actions
I really can't agree that there is such a little affect on Sv% from shot quality
The problem lies with assessing shot quality on a dataset of statistical scale. Position does not directly correlate to shot quality. There are simply way too many factors to be able to create a proper statistical study to assess the effect of aggregate shot quality on sv % because aggregate shot quality can’t be assessed.
Again, you're looking at it on a micro level
Those factors even out over time. It’s not like one goalie only faces Sidney Crosby for 2000 shots.
by ChicagoNativeSon on Dec 9, 2011 11:44 AM CST up reply actions
I'm not looking at it on a micro level
The rubric for assessing individual shot quality underlies any assessment of aggregate shot quality. The rubric for assessing individual shot quality is poor. The assessment of aggregate shot quality must be equally poor, and to make the assertion that shot quality has no effect on sv% when the assessment of shot quality is so poor in the first place is a misadventure.
That IS looking at Shot Quality on a micro level
http://www.arcticicehockey.com/2009/10/9/1077540/frequently-asked-questions-6-shot
Over time, everything but distance is pretty much a wash.
by ChicagoNativeSon on Dec 9, 2011 12:42 PM CST up reply actions
If Shot Quality had no part in the long run
If something existed that showed it in various situations from 5v5 to 3v5 and the SV% remained the same or within a small enough margin of error, I would be convinced, since each of these would by nature of the situation tend to have differing levels/ratios of quality shots to total SOG.
This Article is from 2009, while the other is from 2010. The AIH is looking more at distance to chance, where the other link looked at Angles, Delta-t between SOG, angles between SOG, rebounds, etc… to attempt to calculate higher chance situations and did in fact see a significant difference when a shot was considered quality.
IMO the former is good for a broad relation of Goals to location in a general setting, but the latter more tailored to more specific scenarios in the shot. But I am still looking into this more.
by Toews-makes-funny-faces on Dec 9, 2011 12:52 PM CST up reply actions
Yes, this article is older
since there’s no one that I’m aware of disputing the correlation between shot distance and shooting percentage.
Did you read that study you linked to? He never reached a conclusion about team Shot Quality! The model was done to study Individual Shot Quality.
What the author was doing was “cleaning up” the previous study based on additional data found. In fact, only one of the three new variables made it into the model. And there’s this:
interesting, though, to note that angles from 15° to 30° (on either side of the net) are near the average goal rate of 8.9 percent.
He’s stating right there that shot distance and not angle is king.
The goal rates were rather symmetrical with respect to shot angle, with the most dangerous shots coming from straight on, where there is the most net to see
But in fact, you can see from his data that shot angle does have an effect, BUT the fact is (looking at the graphs in my post), most teams take nearly the same percentage of shots from each area. Therefore, the effect is virtually null.
Per the author, the marginal contribution of Shot Angle is 0.016, which is considerable less than Shot Distance (0.074).
Again, he makes absolutely no claim as to whether or not Shot Quality has a substantial effect on team shooting % over time. It’s more a study of “what are the ingredients of Shot Quality.”
But I’m gonna end discussing this on my part. This has nothing to do with my post. I disagree that Shot Quality has much effect on Sv%. Most everyone seems to believe that it does. Therefore, instead of fighting the overall consensus, I decided to give in and take a look at the numbers from the majority view: that Shot Quality does effect Sv% over the long term. So I posted the data that shows that the Hawks have given up the fewest goals from high quality areas, and now we’re somehow back to discussing what I already conceded in my post for the sake of argument. “Yes, Shot Quality is EVERYTHING, and here are the results…”
by ChicagoNativeSon on Dec 9, 2011 1:30 PM CST up reply actions
This is a tough area to breakdown by numbers
Because too much goes into all the aspects. I am not trying to beat down, but rather have questions answered, since both of these articles directly conflict with one another and you are familiar with the AIH one. I am trying to figure it out, or a means of placing a constant or bracketed variable or ratio or whatever to try to quantify qualitative data from a broad realm.
It took baseballs decades to come up with the advanced sabermetrics it has today, through many trials and such, and hockey is still in the infancy of it and the only other of the 4 “major” sports (not even every team admits to using advanced stats) that really lends itself to advance sabermetrics. I am sure in time something will be developed, but in the mean time, is it not somewhat fun to argue about it and debate it and try to figure it out ourselves? lol
by Toews-makes-funny-faces on Dec 9, 2011 2:00 PM CST up reply actions
based on what?
Once you take hundreds of thousands of shots, all of the things that might impact shooting percentage, like shooting angle or screens or 2-on-1s or individual shooting skill or goaltending, are a wash.
direct quote from link – blatant handwaving
Shot quality is determined by these very things. A shot from X distance can have very low quality if the lane is clogged by three bodies, or high quality only one person is present right in front of the net minder.
If it is too difficult to assess the effect of those aspects on shooting %/sv %, it is ok from a statistical perspective to say that those effects cannot be assessed. To say that they are a wash without citing evidence is horrific.
Why do people harp on getting people to the net? Because when you get people to the net, shot quality goes up, sv % goes down, and more goals are scored. You also create opportunities to clean up rebounds on a goalie who is down. This is the whole point of shot quality. The aggregate sv% on these types of shots is lower.
Now I know what Don Quixote felt like...
Because when you get people to the net, shot quality goes up, sv % goes down, and more goals are scored.
Yes, and that’s why shots from in front of the net have a higher shooting %. That’s in the data! You’re arguing the quality of one shot. The study is looking at a much larger sample – and in that larger sample, all that stuff’s a wash.
Again, my post concedes that Shot Quality is KING and that I’m wrong and all these studies are wrong. It’s conceded, no reason to argue it. So, that being said, you’re right. Now with that concession in hand, if you look at the graphs, what is the argument? That Shot Quality doesn’t matter?
by ChicagoNativeSon on Dec 9, 2011 1:40 PM CST up reply actions
dude
remember, lots of people are mind-blown by the complexity of the three-point scoring system in the NHL.
You seem to think the statistical arguments you are presenting here would be easier to explain. Good luck with that.
We like our people!
Yep.
You get an extra point if none of your players are suspended by the Shannahammer mid-period.
Furious George! What happened to your beautiful face?!?
The statistical argument for shot quality being a wash
is that it is a wash.
That fact doesn’t really apply to the OP of hawks save by zone region as they relate to crawford’s struggles.
To me
This kinda looks like selecting what research you want to accept and disregard. This article is backed up by pretty good science and math as well with a large sample size.
IDK, perhaps is it a combination of both, but I can’t just discount this after going over it a couple times.
by Toews-makes-funny-faces on Dec 9, 2011 10:44 AM CST up reply actions
I'm selecting the most recent one, which is usually what is accepted in science, no?
And even Alan Ryder (HockeyAnalytics), who published the original study of Shot Quality 10 years ago, recalled his study because Shot Quality has no more effect than “luck” over the long run.
IMO, if Gabe Desjardins (BehindtheNet), Vic Ferari (TimeOnIce), Derrick Zone, and a host of all the other big names all have disproved it, I think I’m going to go along with their studies instead of just picking what works for me. I have no dog in the “does Shot Quality have an effect over time” argument, because in this case it doesn’t matter. It appears the Hawks have greatly reduced Shot Quality from last year.
But let’s look at the other side of the coin and go with the assumption that Shot Quality does have a big impact over the long haul. Looking at the data in my post, that makes your argument even weaker, doesn’t it? So I’m confused on what your position is?
by ChicagoNativeSon on Dec 9, 2011 11:38 AM CST up reply actions
I am back to base 1 in this one, need to look at from the begining
So I have no opinion on the matter at this time. I do not not know what data or what in depth is being used in the differing studies, just the basic overview. Perhaps in their own respects each is right because they are using differing metrics, IDK.
Unfortunately Shot quality is a harder item to put into a simple number. Sometimes a 15’ shot in front of the net is nothing for a goalie to stop while the same shot at another time is nearly a sure goal, because of so many factors. I do know simply saying the place of origin of a shot is only part of what defines (or should define) a high quality chance, but it is not the only thing.
As for my previous argument, you are correct the data in your post does weaken my conclusion more from a couple days back, while the data in the link strengthens it.
As for “luck” that is another argument, and in sports IMO it is used allot, but to me what some consider “a lucky play or bounce” or such is more to do with the precision in the execution of a skill, then true random chance, though random chance does at times does rear it head (bounces of the stantions into the net)
by Toews-makes-funny-faces on Dec 9, 2011 12:30 PM CST up reply actions
Sometimes a 15’ shot in front of the net is nothing for a goalie to stop while the same shot at another time is nearly a sure goal, because of so many factors. I do know simply saying the place of origin of a shot is only part of what defines (or should define) a high quality chance, but it is not the only thing.
Yes, as I’ve been saying, I completely agree with the first part, but over a large sample, distance is what drives Sv%, everything else washes out (link above in reply to oregon hawk)
And “luck” as I used it compared to Shot Quality is explained pretty well here. Basically, Gabe came up with the same results by flipping a coin as he did when factoring in Shot Quality and other goodies.
by ChicagoNativeSon on Dec 9, 2011 12:53 PM CST up reply actions
The question I have because to me it is counterintuative
Is the even out a result based on the method used (ie design since all shots are weighed evenly, which to me is wrong) or is it a relative fact based on situations for each SOG? Reading it is seems more a designed to even out of data, rather then a way to extrapolate variances in the data.
I think the ONLY way this could be settled conclusively is every goal is mapped out, not in location, but Defensive position, Goalies Field of View, deflections, rebounds, shot location, etc…… and then extrapolate the most common traits of a SOG stopped and SOG that results in a goal. And from their see how defenses limit the most common occurrences to see the strongest fault in GA. But this would take a dedicated effort well well beyond anything I could do, it would require somebody to analyze not only this years goals but several previous to yield good results.
by Toews-makes-funny-faces on Dec 9, 2011 1:05 PM CST up reply actions
you are understandably stuck on the "micro" aspect.
look at these graphs from a broader view.
skeletons don't like closets.
by Where Triples Go to Die on Dec 10, 2011 4:32 AM CST up reply actions
I want the micro to break out this aspect
The macro does not break out QOS only shows GA and SV%. I am interested in the micro of the WHY GA and SV% mainly QOS.
by Toews-makes-funny-faces on Dec 10, 2011 7:22 AM CST up reply actions
How do they measure luck?
I want to know so I can hit the boats. I want to know what my luck is.
Hold My Stones
pretty funny
the author of this article is a close, personal friend of mine since childhood. So, I’m gonna ask him about it.
Don’t see how this really gainsays CNS’ main point, that over the course of many games, SV% is a reliable measure of goalie performance, and his corollary, that sure as the sun rises, many fans will make an exception for their team, because they watch the goals given up, and on virtually every goal, somebody besides the goalie can be assigned a share of the blame.
We like our people!
I think there are problems with the data.
I was playing around with the same data myself a few days ago. If you notice on the ice tracker dropdown, the only seasons listed are 2009-2010 and 2010-2011. It shows the latter by default, not the current season, as far as I can tell. I think the data you show here is actually the 2010-2011, and for last season you’re actually showing the 2009-2010 season. I could be mistaken, but I spent a while looking at it when I noticed the issue and I think that’s the case. Another minor issue is that shootouts are included in your shots.
I scraped the data, so I have it for all teams if you’re interested. Give me a few minutes to put it together and I could make a google doc or something.
The other problem is that, since these are percentages, it only shows the distribution of goals allowed, so everything is relative. You could have a great slot-defending team, but if you have an even better point-defending team, your relative slot rating might still look bad compared to other teams.
I think you might be right about the data
Crap. So now, I’m gonna have to manually go through each game and plot the goals scored. Guh. Good catch though and that could change everything.
I doubt SO’s are included though since SO goals aren’t officially scored. How did you conclude that?
It shouldn’t matter if percentages are used. In fact, they’re better than showing raw numbers because that tells us nothing about the percentages which is what we want to know. If a team is good at protecting the slot, then they will give up a lower percentage of goals from that area, the most dangerous on the ice.
Looking forward to your google doc. Thanks.
by ChicagoNativeSon on Dec 9, 2011 1:58 PM CST up reply actions
Actually it shouldn't be that difficult to amend the findings
I can still use the random samples from the other teams since they’re still relevant and just re-plot the the Hawks goals from this season. Not too difficult to do.
by ChicagoNativeSon on Dec 9, 2011 2:00 PM CST up reply actions
Crap. So now, I’m gonna have to manually go through each game and plot the goals scored. Guh. Good catch though and that could change everything.
Nah, the data for this season is actually on the website, it’s just not accessible through the ice tracker app. So it will be included in the spreadsheet.
I doubt SO’s are included though since SO goals aren’t officially scored. How did you conclude that?
’cause if you de-select SO in the ice tracker the numbers change. And the data stream has periods 1,2,3, 4 (OT) and 5 (SO). The numbers checked out iirc.
It shouldn’t matter if percentages are used. In fact, they’re better than showing raw numbers because that tells us nothing about the percentages which is what we want to know. If a team is good at protecting the slot, then they will give up a lower percentage of goals from that area, the most dangerous on the ice.
Here’s a simple example of what I mean. Lets say there’s just two areas on the ice, near and far. League average, 75% of goals are near and 25% are far. Your team has great d-men, and has given 100 goals so far, with only 66 from the slot. Your goalie gets hurt, and his backup is incredibly nearsighted and gives up a ton of goals from long distance, while performing exactly as good as the previous goalie on close shots. So over the next 50 goals, say they are split evenly.
Before you were 66%, 33%. Afterwards it’s 60%, 39%. Your slot defense looks better, even though it performed exactly as well, because your point defense got much worse.
Looking forward to your google doc. Thanks.
15 minutes or so.
Here's the data.
Goals by ice location Google Doc.
The “GA Percentages sheet” is probably what you want, it has the same kind of numbers as the ice location charts, on defense. They’re a little different because I’ve excluded the SO goals. They’re separated by season (for 2010, 2011 and 2012) and even strength vs. powerplay (i.e. meaning the defense is on the PK). The raw data sheet lists the individual goals that the percentages are calculated from.
I’ll add the data for the net locations when I get a few more minutes.
If you need anything else, just let me know. I’m happy to help.
Wow, that's awesome!
What did you use to scrape the site? Python, like Verstig? Life would be so much easier if I learned this stuff.
OK, at first glance, the numbers from this season are very similar to last year. 70% of goals at EV were scored from the center of the ice in 2011, 69% this year. Slightly worse low (3%), slightly better high (4%).
And then you look at 2010, a defense that led the league in fewest SOGA and they gave up 69% of goals in the low slot alone and 75% total in the middle of the ice.
And then look at some of the teams with goalies with extremely high Sv% and just as many of them give up a very high percentage of goals from the slot as give up a low amount. So basically I’m not sure what this is telling us at this point.
by ChicagoNativeSon on Dec 9, 2011 3:08 PM CST up reply actions
Hey zacked
I’m assuming X and Y in the raw data page are shot coordinates? If so, where is 0,0 located on the ice? I’m seeing shots from the slot with X=69, Y=-8, so I’m confused. Thanks
by ChicagoNativeSon on Dec 9, 2011 3:15 PM CST up reply actions
Not sure.
I think the Y is the width of the rink, and X the length.
Y goes from -40 to 40, so 0 would be center ice. An NHL rink is 85ft wide, so that would fit.
X goes from 0 to 100, I think 0 is the redline and 100 is the end boards. The goal is around 90 ft. Which is also roughly the right size, despite the fact that the images on the icetracker end at the blue line.
It’s not like any of this stuff is documented, though, I’m just guessing based on what’s there.
I feel like the dumb kid with the crayon up his nose in class while reading this.
I do stuff for CheerTheAnthem
by HjammerTime on Dec 9, 2011 3:33 PM CST up reply actions 4 recs
..Mr Eager..
enough of the niceties: time for the eye-gouging..
and yes, I probably *should* be asleep right now!
by mightymike D on Dec 10, 2011 2:46 PM CST up reply actions
lol
i literally /facepalmed after reading zacked’s post. the negative threw me off. i made it more difficult than it was.
Turco was good, but Crawford has a force field...
by Coz_Bulls_Fan on Dec 9, 2011 10:55 PM CST up reply actions
uhhh
enough of the niceties: time for the eye-gouging..
and yes, I probably *should* be asleep right now!
by mightymike D on Dec 10, 2011 3:10 AM CST up reply actions 1 recs
zack
I think I can quickly savage this by simply using the EV, PK, PP and SO percentages from this year for the Hawks. Can I bother you to provide that?
At least it’ll be apples to apples.
by ChicagoNativeSon on Dec 9, 2011 3:39 PM CST up reply actions
By percentages you mean the zone percentages, like in the spreadsheet?
If I follow, the PP and EV are already there. You want the PK and SO as well? I don’t think there’s anything meaningful there.
It was just to do a quick fix
to match the data with what is already posted. Therefore I would just have to change out 2011 and 2012 for the Hawks. I can see that the results are very similar when comparing EV and PK combined from 2011 and 20102, but they don’t matchup with the percentages from graphs up above because PP and SO are missing.
by ChicagoNativeSon on Dec 9, 2011 4:37 PM CST up reply actions
Just the hawks, just this year, everything?
Sorry if I’m not following you. This is everything for this year for the hawks. Would match the very first picture, except it’s this year.
Left Circle – 6%
Slot – 63%
Right Circle – 7%
Left Point – 6%
Mid Point – 7%
Right Point – 7%
I am still crunching numbers
But on the whole of the season this is what I have gotten so far.
No pretty overlay of the rink yet, but the Top zone is beyond the Goal Line
The next three are the Offensive (defending) Zone
The bottom is the Neutral Zone to the Center Line.
I broke the O-Zone into 9 areas, evenly 21.33’ up/down 26.67’ Left/right, but overall should be a reflective idea of Goals Against still.
Apparent ENG and invalid X,Y data was filtered out.
I plan on breaking this down further (EV, PP, PK NHL avg, Period, etc…), but am still building on that. As noted this is a spread of percentage of goals scored against, not of SV% or Shot location %.
by Toews-makes-funny-faces on Dec 9, 2011 8:20 PM CST up reply actions
Ironically on the PK
The Hawks are well above NHL AVG near the crease 47.62%, 8.25% above the league average. But in the middle of the Zone terrible at 19.05% 8.93% worse the the NHL AVG, also the right Point is awful at 14.29% 10.64% above the NHL Average
by Toews-makes-funny-faces on Dec 9, 2011 9:26 PM CST up reply actions
So basically, it appears to tell us nothing right? (no snark)
The guys at AIH are gonna be so surprised when I let them know! (snark ;)
On a more serious note, I reached that conclusion earlier comparing 2011/2012 to 2010 when the Hawks had the best defense in the league yet had one of the highest percentages of goals from the low slot.
When all is said and done, shot differential is one of the biggest factors in how a team performs. So limiting total shots (not specifically “quality shots”) is the biggest goal of team defense. And whether a team gives up a high rate of shots or not has minimal effect on Sv% – it more just determines whether or not they’re gonna give up a lot of goals.
by ChicagoNativeSon on Dec 9, 2011 10:04 PM CST up reply actions
Shot Diff is going to be a pretty good indicator regardless IMO
Unless the D is a complete bag of dicks, and just lets a sniper waltz into the slot time after time after time, it is more then reasonable to assume the larger the Shot Diff is, it would in many more cases then not also lead to more quality scoring chances. I will stop short of saying always, since in nearly every data set you get, you get outlyers, they may not follow the vast majority of the rest and average out over time, but can be significant in their own right for that point in time, by explaining other anomalous data and indicating a fault/error or other problem in something.
by Toews-makes-funny-faces on Dec 9, 2011 10:35 PM CST up reply actions
Hence
What I term the Detroit Model debate (which I know by the comments section, you have read).
In a salary capped league, you have to choose your poison. And since shot rate seems to be the more sustainable that high shooting/save percentages, put your money in players that fit that model and try to get by with “average goaltending.” (I think I’ve heard that somewhere before!)
by ChicagoNativeSon on Dec 9, 2011 11:33 PM CST up reply actions
That's crazy talk!
That will never win the big shiny thing at the end of the year
by Toews-makes-funny-faces on Dec 9, 2011 11:34 PM CST up reply actions
I think this does also show the league average through the three years is pretty consistent in all areas of the zone
But the Hawks show pretty decent variance from year to year compared to the team and league, in some areas more then others.
For example this year.
Hawks GA% in the crease area in the 1st period is 68.18%, the NHL average is 52.03%.
For the 2nd period where the league average rises about 8% to 60.49%, the Hawks actually falls about 8% to 60.00%, then in the 3rd the NHL the Hawks are back up to 66.67% and the NHL slightly increases to 61.75%.
Overall things probably average out and remain fairly consistent. But when it is broken into more specific areas, the variance is more apparent, and one thing it shows so far for 2011-12, the Hawks give up a much higher amount of goals in/around the crease then most NHL teams.
by Toews-makes-funny-faces on Dec 10, 2011 9:00 AM CST up reply actions
So ...
All this to say that it’s shot differential that more or less dictates success. Which is to say, essentially: if a team spends significantly more time in its opponent’s zone than it does in its own, that’s good?
Heh.
www.mjt.org
Yes,
This is the same method and coordinate system that the link laaarmer and myself posted.
by Toews-makes-funny-faces on Dec 9, 2011 4:49 PM CST up reply actions
Wish I could edit...
Pretty sure I’m wrong about the X axis. No way it goes all the way out to the red line, ‘cause there are 4 goals just this season with x<4. No way there have been 4 goals from the red line, even if they’re empty net (which I bet they all are).
Actually, scratch that. I just found this goal (the one at the red line), which was (2,15) in the data. Of course, if you watch the video that shot actually came from below the left circle. Probably a typo in the data entry, and a good reason not to trust completely in any data recorded by stringers.
I guess this is why meatheads think Burish is awesome, he scores from the red line!
I have to ask
Where the Hell did you get these numbers!!! They are great!
by Toews-makes-funny-faces on Dec 9, 2011 4:32 PM CST up reply actions
Does the 2010-11 and 2011-12 seasons exist for this data as well, since this is for the 2009-10 season?
Also it seems to be missing at least one team (ATL)
by Toews-makes-funny-faces on Dec 9, 2011 4:35 PM CST up reply actions
It's in the same sheet.
The 2010-11 and 2011-12 are all on the same sheet, just scroll down.
There’s nothing for Atlanta in the data. Winnipeg shows up in this year’s data, but the previous years are just blank.
On your last point
I don’t think Emery is nearsighted, so we don’t have that to worry about. But who is in goals shouldn’t play a significant factor over time. Again, all those studies conclude that over time shots from a specific distance correspondent to a specific shooting %.
by ChicagoNativeSon on Dec 9, 2011 2:54 PM CST up reply actions
I think we're talking around each other, but...
Again, all those studies conclude that over time shots from a specific distance correspondent to a specific shooting %.
Yes, but these charts don’t show shooting percentage. They show the percentage of total goals allowed by the location they were shot from. My point is only that, as with any distribution, all the numbers are relative to one another. You can’t change one without changing the others, so you have to be extremely careful when making comparisons between teams.
In fact, a great defensive team might show a really high percentage of goals from the slot, because only dirty goals get scored on them!
I added the data for the goaltender charts on the “net ga percentages” sheet.
I get your point
although I would suggest there is some relationship. Hence why I stated in my post “Shot Quality ‘via’ Goal Location” since inference was being used.
So I guess the question is “Is it easy to scrape shot location data from nhl.com too?”
by ChicagoNativeSon on Dec 9, 2011 3:11 PM CST up reply actions
Scrapin' on my scraper script
What did you use to scrape the site? Python, like Verstig? Life would be so much easier if I learned this stuff.
Yeah, Python. I’m not a programmer at all, I taught myself enough to do this from playing with MLB pitch/fx data. I would kill from something like that for hockey, which is hilarious because it is basically FoxTrax…
So I guess the question is "Is it easy to scrape shot location data from nhl.com too?"
Easy, not really. But I’m 99% sure I wrote a script to do it last season already. As long as the data hasn’t changed much it should be relatively easy to get. The only issue is that it is going to be a LOT of data. I’ll see what I have.
Hey zacked
Do you have a script that converts the JSON files (which, presumably, you’re using?) into a CSV or Excel format? I’ve been reading the raw data directly (into Matlab) but sometimes Excel is just a lot easier to work with. If it’s something you’d rather not do I totally understand, but it might be cool for us to put together a few useful scripts that people could use…
by VerStig on Dec 9, 2011 8:02 PM CST up reply actions 2 recs
If I had 10 recs to spare I would contribute them to greening this
Please people, think of the children.
Verstig, you sure you want to create that monster? If you’re pulling your hair out watching us butcher stats now, with these additional toys for us to break, we’ll have you bald by the all-star break!
by ChicagoNativeSon on Dec 9, 2011 10:07 PM CST up reply actions
Yep.
For that data specifically my script just dumps a CSV. For the full PBP stuff it goes to mysql because that would crush Excel like a rice cake. Unfortunately that particular script is on my work PC. I can send it to you on monday (and if I forget, just holler at me).
I’m more than happy to share whatever I’ve written so far (after I’ve cleaned up some of my unreadable code). The best option would be to set up a communal space, then dump the data there for people to use. Does anyone have access to a mysql server? Most of the reason I’ve never done anything with this data is ‘cause I don’t have a good place to put it.
Next up I want to write something to capture the new shot data and index the highlight clips by player.
Oh I've already written a PBP parser
I use SQLite since it’s portable and easy to keep on my home PC… but I think it’d be a good idea to put some kind of communal space together. Ultimately a website that can access your mySQL database perhaps, if the NHL doesn’t complain…
I was kind of wondering along the same line of thought
These charts are for % location of where goals are scored. Perhaps some correlation to % location of where shots were taken would (should) be used as well. If the Hawks are giving up 15% more high quality shots (low slot) this year than last year, it’s possible (in my mind) that they could actually be conceding fewer % of goals from the slot. Much like what zacked discusses above…
Also, chalk me up as one of the people that isn’t really sure about the whole “high quality” shot charts and their advanced metrics. Obviously, higher quality shots occur close to the net. What I’m not sure any metric will ever demonstrate is the desire to take “poor quality” shots from the point, wide angle etc. with the expected return of generating more “high quality” shots from rebounds in the slot. If the team is full of horse-shit pussies that won’t crash the net, you amass a ton of “low quality” shots and perhaps a few more percentage points of goals scored from “low quality” spots. If the “poor quality” shots are taken as part of an offensive scheme to get to the net, and the players actually do “get to the net”, over the long term, you’re inflating your “poor quality” shot percentages (perhaps not increasing poor quality goals) but drastically improving your goals scored in high quality positions. In some cases, so high quality the opposing goalie doesn’t even have a chance to stop it.
IDK, I’m a big fan of stats and advanced metrics, used them repeatedly to bludgeon my fantasy baseball opponents until they figured them out, but I’m really not that confident that advanced hockey metrics will ever evolve to the utility of those seen with baseball.
You are next.
by M7 on Dec 9, 2011 4:41 PM CST up reply actions
All these charts and stats
hurt my fucking head. But looking at the first chart, without analyzing exact angles and luck involved, I think it comes down to poor goalie positioning or a few more screened shots from the side going in.
But excellent work collecting all these stats. I have neither the time or the patience for it.
Lead writer of nothing, commenter on everything.
Useful data, for sure
I do have a question though. Do these numbers combine shorthanded time as well as even strength? Just curious on that front. With the way the kill has treated Crawford over the past 3-4 weeks, I have to think a lot of the goals in the slot of coming while we’re on the kill. Apologies if I missed the mention of this in the post.
by JesusMarianHossa on Dec 9, 2011 3:38 PM CST reply actions
Everything is in there, including f'ing SO's
I made an error and took everything instead of just EV and PK, but we’re gonna have to live with that unless someone wants to redo everything.
by ChicagoNativeSon on Dec 9, 2011 3:42 PM CST up reply actions
/quickly steps back
It’s 3:42 on a Friday. If this were Monday morning and I was looking to evade work, I’d totally do it.
by JesusMarianHossa on Dec 9, 2011 3:43 PM CST up reply actions
harpy tediidays..
enough of the niceties: time for the eye-gouging..
and yes, I probably *should* be asleep right now!
Maybe a more clarifying way of putting it is needed
Reading the argument above in these comments, it strikes me that maybe word choices are getting in the way of clarity.
CNS states that the data (crunched by several different people) reveals that “Individual Shot Quality does indeed exist, but over the long run it evens out and has little statistical effect on Sv%.”
Unfortunately that particular phrasing does make it sound like a claim that a goalie’s save percentage is not much affected by the quality of the shots fired at him. Which is an obviously-nonsensical idea, and CNS rightly responds that no it’s not what he means.
It also sounds like folks responding to this are forgetting that all of these statistics are regarding NHL play in particular; that this is not a claim about how it goes in the playing of ice hockey generally. That makes a BIG difference with this sort of highly-specific analysis. E.g. the fact that “lineup protection” has been shown to be a myth at the MLB level does not at all preclude its being a real factor in college ball or Little League play or whatever.
Anyway I think what CNS and the others who have reached this conclusion are trying to say is this: “Over the course of an NHL season the quality of shots actually taken by different NHL teams largely evens out; there are not significant differences in the average shot quality generated by different teams at the NHL level and over the course of a season. This documented fact means that shot quality is not a significant factor in explaining the differences in season save percentages between different regular NHL goalies.”
Right?
by Paul the Fossil on Dec 9, 2011 4:13 PM CST reply actions 3 recs
I wish I could rec this
I think it’s a great explanation of what CNS is gettiing at and everybody should read it.
I’ll have to see if I have anything to add… probably not but if so I’ll grab my soapbox when I get home.
As for zacked’s data, I assume he got it the same way I’ve been doing - there’s a hidden file that the ice tracker uses that contains all the data in a format called “JSON” and if you how to read that file, you can get the shot data. (Also, it contains links to highlight clips, for all you vid and gif-makers out there.)
by VerStig on Dec 9, 2011 5:40 PM CST via mobile up reply actions
Let me begin by saying
FUCKING ANDROID!!!!
Now, as I was saying before I was so inconsiderately zapped….
I’m just starting to delve into this. Fascinating stuff — thank you to CNS, to other commenters, and to PtF for distilling things.
But the argument that shot quality evens out over the long run is not sinking in. Surely, Toews, Kane, Hossa and Sharp are not only better marksmen than the top four offensive players of other teams, but they create better chances too.
And on the other side of the coin, yes, over the course of the season, all teams may play a roughly similar cross-section of NHL Ds, but in evaluating Crow’s performance, we need to be looking specifically at whether the Hawks’ D is giving up better or worse chances than are other Ds.
So if a set of stats indicates that all teams give up a similar average shot quality, I am skeptical whether that set of stats really captures shot quality. Some Ds do a better (or worse) job of keeping the crease clear. Some give away fewer (or more) breakaways.
In other words, what Cliff says a few posts below, only less succinctly.
I think it would add a lot to see charts like what CNS has given us, but showing the number of shots taken from each of the six areas. This may already exist somewhere on SCH and I just haven’t found it yet.
Hey, isn’t it time for the next game!?! What about those great 10:30 starts!?!
If graffiti changed anything it would be illegal
The thing is, when you talk about good vs. bad players
I don’t think anybody is questioning that. If I remember correctly, didn’t Gabe/Hawerchuk at AIH/BtN post something about how better players tend to have better shooting percentages (even if those revert to a mean, better players have higher means)?
In other words, players can impact their shooting percentage by being good shooters, but where they are shooting from doesn’t.
Still working my way thru SQ101
I’ll put AIH/BtN on my reading list
If graffiti changed anything it would be illegal
I guess it would depend
Better players will probably find the softer spots to achieve those better looks, whether it is back door or just sneaking into the slot, where on “common” player does not find those places as frequently. Look at Toews-Sharp-Kane-Hossa, they all know exactly where to get in between the defense to get that quick shot off before the Goalie or D can react, in turn if true, are increasing their quality scoring chances in the term on top of being able to pick their spot.
So I would say it is a mix of shooting skill and just being a total badass at hockey!
by Toews-makes-funny-faces on Dec 9, 2011 11:09 PM CST up reply actions
Who needs numbers to realize that?
Who the hell cares about that? The quality of shots even out………….. unless you are Columbus, Carolina or Anaheim.
My point has been and will be that if you allow “quality shots” against your goalie, hissv% will be lower than if you allow unscreaned shots from distance or low angle shots.
Hold My Stones
This has been thoroughly entertaining
and I’ve never laughed so much reading a thread. I don’t dare look at the links, charts, graphs or whatnot…but I wholeheartedly love and appreciate the hockey nerd-dom going on here and elsewhere. I won’t pretend that I understand any bit of it, but the discussion sure has been entertaining and CNS, and Zacked, thanks for your work. I sincerely appreciate it. This has been wonderful.
Oh and hey, didja see Shooter bury that rebound last night?!
I call that a high quality shot!
"I killed a man 'cause he killed my goat."
LMAO
Perspective!
Yes, I will CONCEDE that was one high quality shot!
by ChicagoNativeSon on Dec 9, 2011 5:14 PM CST up reply actions
it just seems to me
that the Hawks have given up a disproportionate number of high-quality shots this year. know what i mean?
We like our people!
by cliffkoroll on Dec 9, 2011 5:27 PM CST up reply actions 1 recs
Ha! Ha!
nice retort.
In all seriousness, I like to think of myself as a fairly intelligent guy, but this shit is just way over my head and mad props to you, CNS, zacked, et al, for this type of deep analysis. I have never been a statistics person and I work with them daily. However, in my work, I report what I see – very little analyis involved. I think it’s wonderful that you guys break this shit down in the manner you do so that may help us with the crayons better appreciate the minutiae.
See if you can guess what I am now.
by IndianHeadCrest on Dec 10, 2011 11:31 AM CST up reply actions
Aggregate Sv% Shot selection poor Aggregate % quality Aggregate poor Rubric assessment quality aggregate %quality rubric
"What is icing?"
"Well, uh... icing appen when uh the puck come down... bang, you know, before the other guys, nobody there, you know. My arm go comme ça then the game stop then start up."
I'm really confused
As far as I can tell, CNS’s original post is talking about how this year’s D is doing a better job of limiting opponents’ shot quality (a really awesome piece of observational work btw), and yet people are complaining about his claim that shot quality has no effect on SV%? Isn’t that a totally different topic?
I can see where the confusion is though, and PtF really did a good job of explaining the difference — that individual shot quality matters for individual shots, but overall shot quality doesn’t determine how good a goalie is doing.
Anyway I’m reading up on some of this stuff now, I think I’m starting to get it, but it’s definitely very counterintuitive. I think I may be able to come up with some more intuitive examples — CNS, would you mind if I put up a FanPost if I ever figure this out? I think you’re making a really important point here and maybe all we need is a really good way to explain it…
Well perhaps the D is not doing better
An error was discovered, the 2011-12 diagram was actually the 2010-11. When the Goals are plotted out for this season, the Hawks GA is worse in close then last year based on percentage of the whole by a noticeable amount. The good thing is their is still 2/3 of the season left to help correct this “anomaly” to more 2010-11 levels.
Ironically, this years Goal Against distribution is very similar to 2009-10, you know the really fun season! But we also had that other pesky goalie situation as well
by Toews-makes-funny-faces on Dec 9, 2011 8:56 PM CST up reply actions
I think I've got it figured out
I’m making some dinky charts for a FanPost now…
The reality is, there is a lot of randomness and that’s what throws off people’s intuition. I don’t think the statisticians (the big name guys) always do a good job of dispelling the misleading aspects of their argument, hence the confusion.
But I think I know how to explain what it is they call “luck”!
Did you read the link I posted for TMFF about "luck" up above?
I thought Gabe did an excellent job explaining the concept of luck in that article. When many people hear “luck” they immediately assume that one means “skill not involved” and that’s obviously not the case. It’s “Can this model or information be more predictive than a coin toss?” if I understand it correctly. Close?
If you could explain it better that might help eliminate the auto defense mode that often occurs when the idea of luck is brought up in discussion.
by ChicagoNativeSon on Dec 9, 2011 10:21 PM CST up reply actions
I just read it again
Perhaps this simple sentence from the article
We’re back to talking about “shot quality” (which I liked to call shot location)
is at the root of the debate. Some may be taking SQ and directly relating it to Shot Distance, while others view SQ as something very different. I am in the later group, (at times I think a 60 footer is harder for a goalie to stop than a 10 footer based on various reasons, thus a Quality Shot compared to a non quality shot)
I am just going to give in and say Hockey does not yet have stats to measure Shot Quality, nor can it be extrapolated from any existing stats, too many factors are part of a deciding what a quality shot, from shot location-type-goalie positioning-10 players on the ice positioning-deflections/redirect/rebound. Just too many variables to put into a nice neat number or set of numbers on it…………..yet. This is just one area that will continue to be battled over and over with different numbers, logics, assumptions etc…..
I guess the first thing is to define a “Quality Shot”, and then determine who or what can influence it and how that can be measured quantativley from the time the shot is taken until saved or scored.
by Toews-makes-funny-faces on Dec 9, 2011 10:48 PM CST up reply actions 1 recs
Maybe I don't need to write my FanPost!
I probably still will, but you hit the nail on the head here. I think there’s a conception among statisticians that the other determinants of shot quality will even out when you quantify it as “shot location,” but those other determinants are exactly why it doesn’t have any effect on shooting/save %.
If that is in fact the conception
It removes WAY to many variables and assumes it will even out with out any qualitative data to justify it. IT is basically building a formula to almost intentionally average them out it seems to make them a non factor in the final SV% product, where it does not really address the issue of “quality shot”.
by Toews-makes-funny-faces on Dec 9, 2011 11:02 PM CST up reply actions
This drives me nuts too.
Some may be taking SQ and directly relating it to Shot Distance, while others view SQ as something very different.
It’s not that shot quality doesn’t matter, it’s that shot quality is not captured in the data that the NHL records. We know that rebounds have a much higher shooting %, and that’s because they are higher quality chances, for example, but most of the variables that influence scoring aren’t captured by the stringers.
Distance, absent any other information, doesn’t tell you much. There’s shots from the point that are more dangerous than much closer shots. That, and NHL scoring is so damn noisy that it obfuscates lots of things.
Really what we want to capture is the degree of “oh shit!” feeling you get when an opponent sets up a shot, or how much of a boner you pop when Sharpie winds up, and see what effect that has.
That all said, I do think shooting is a small part of winning hockey. Controlling the run of play (skate of play?) is where you win games.
by zacked on Dec 10, 2011 12:30 AM CST up reply actions 1 recs
I just wanted to say good luck, and we're all counting on you
a rejuvenated VerStig as Hannibal, CNS as Mr. T,, TMFF as Face, and zacked as the crazy guy.
I love it when a plan comes together.
But beware of the rocky shoals of this “shot quality”. IIRC, no less an authority than Derek Zona himself took this on over at C&B a year or so ago, and I wouldn’t say he won.
We like our people!
Your last paragraph...
Let’s say you and I are great at controlling play, so much so that we completely cancel each other out. I manage to get 1 shot on goal, you manage 0. Who has any chance of winning that game in regulation.
/deep thoughts
by ChicagoNativeSon on Dec 10, 2011 12:24 PM CST up reply actions
Oh, and Dan Boyle doesn't play for my team
by ChicagoNativeSon on Dec 10, 2011 12:25 PM CST up reply actions 2 recs
You beat me to it!
So I will let you have Patrick Roy and his Statue of Liberty impression instead!
by Toews-makes-funny-faces on Dec 10, 2011 12:29 PM CST up reply actions
That would be awesome Verstig
Maybe one fanpost from you will get ya back in the groove… and lead to two… eh, maybe a third… oh what’s just one more…
FYI, if you go to AIH and type “shot quality” in the search bar, it’ll give you some good leads to info – and to some secret pages at BtN which break down individual shot quality for every player in the league.
by ChicagoNativeSon on Dec 9, 2011 10:14 PM CST up reply actions
CNS's VHS copy of "A New Hope" busted
and he got bored waiting for the (inferior) replacement DVD.
Maybe it's booze, maybe it's glue, maybe it's gasoline. Maybe it's a gunshot to the head. But something. Something to relieve the pressures of their everyday life, like having to tie their shoes.
by hairhelmet on Dec 10, 2011 12:31 AM CST up reply actions 2 recs
you ever seen star wars in hd?
it was not meant to be seen that way, nearly ruined my childhood i tell you.
by putmeinthemadhouse on Dec 10, 2011 12:57 PM CST up reply actions
Ruined Childhood..
Phantom Menace and Hayden whathisface photoshopped into Return Of The Jedi pretty much did that for me.
enough of the niceties: time for the eye-gouging..
and yes, I probably *should* be asleep right now!
by mightymike D on Dec 10, 2011 2:48 PM CST up reply actions
Noticed I said VHS
because what you guys are talking is nonsense. George Lucas’ talent died during the birth of DVD. And while I’m at it, fuck THX. Colin Campbell had more authenticity.
/hockey’d
/soapbox’d
Maybe it's booze, maybe it's glue, maybe it's gasoline. Maybe it's a gunshot to the head. But something. Something to relieve the pressures of their everyday life, like having to tie their shoes.
CNS you could have saved time on all the research
and concluded Crawford gives up way too many rebounds. ;)
thanks for the post though, it was very interesting.
skeletons don't like closets.
by Where Triples Go to Die on Dec 10, 2011 4:37 AM CST reply actions
Nice stuff, CNS. If there’s anything that I see may skew your results a bit is their poor PK so far. I would imagine a power play allows a greater percentage of shots to get through from the point, which would lower the percentage from the middle of the ice.
The overall point your making is about right. I keep putting myself through the torture of watching the elite goaltenders play and there’s no doubt that they too have defenses that breakdown on multiple occasions per period. The difference being that they’re so sound positionally that they do become an effective last line of defense (which is what your goalie needs to be).
On the PK the HAwks are better close into the crease in % of GA
But the Mid slot (21-42’) and Right point are problem areas so far. But this is a much smaller sample and may not be very indicative yet.
by Toews-makes-funny-faces on Dec 10, 2011 9:03 AM CST up reply actions
i see
so the PK numbers would have a fairly large effect on CNS’s overall numbers, only because we’ve allowed so many PP goals. Or am I misreading what you’re saying?
Some effect yes
21 of the 90 GA have come from the PK, so it will change numbers. But if anything it actually dampens the low slot/crease area overall, since the PK has let <48% in from there, but on EV >67% come from that area.
To me this begs the question why? The NHL avg in the same area (crease) drops ~3% on the PK same as the mid slot, while the high slot increase ~4% the others are mostly the same ~1% change or so, but for the Hawks it is the mid slot (11.7%), high slot (3.3%) and Right point (12.8%) that increase significantly while the others are similar to EV.
Why these variances and as large as they are? That’s my question now
by Toews-makes-funny-faces on Dec 10, 2011 9:29 AM CST up reply actions
So that suggests our two forwards collapse too readily on the PK when there’s pressure or clear chances from behind the net and/or the side boards.
www.mjt.org
I am not ready to go that far yet, to say who
Other then the center of the ice is an issue. Only 21 GA exist so far, so 1 goal is 4.76%. But saying that, as many goals have been scored from the mid slot as have been scored from the circles, high slot and left point combined so far.
by Toews-makes-funny-faces on Dec 10, 2011 9:49 AM CST up reply actions
It could suggest, though, an overplaying of the puck when it goes to certain areas of the ice. We’d have to look at each of the 21 goals. And exactly, I realize we’re early in the season … which exposes a significant problem when looking at stats right now with an eye toward conclusions about very specific strengths and weaknesses.
www.mjt.org
this clicks with my eye test
the Hawks tend to be more aggressive in their own zone when shorthanded than most other teams.
At the end of October, remember, things looked very different:
The power play is hilariously bad. Another 0-5 tonight, but the three disallowed goals do say something. Right? Right??? The Hawks have scored 4 power play goals this year (and allowed 1 shortie), more than St. Louis and New Jersey and less than everybody else.
The penalty kill is unsustainably good, like a .500 hitter in April. Two goals allowed this year, best in the league. And oh yeah. Three shorties, also best in the league. Put it together and 4-on-5 has been almost as good as 5-on-4 this year.
I think the PK got cocky and lost its discipline after the heady start, becoming indiscriminately aggressive, and it took the Hawks most of November to fix, but it looks ok now. Toews and Keith have been the worst offenders- I don’t see that trend holding.
We like our people!
Exactly. Those kinds of mistakes can creep in so easily. Aggression was good, but it dipped into more aggression, and it’s not exactly like you can identify that line by watching game tape. I mean, you see where the mistakes were made, but the mindset that led to the mistake you don’t want changed. It’s like they’re measuring tensile strength, but with eyes, not tools.
www.mjt.org
They weren't the only ones
after scoring more shorties than allowing goals on the PK, we were a pretty supportive bunch around here. Don’t know how fan-support reaches the players, if it all, but even if not, they are humans and have similar mindsets. You take chances and score more than you allow on the PK? One can’t help think they have a valuable weapon. We all know when we won the Chalice of One Year of Infinite Happiness, we led the league in shorties. I wonder what the stats are for win percentages when only 1 team scores a shorty in a game.
Stat fairy, make it happen.
Maybe it's booze, maybe it's glue, maybe it's gasoline. Maybe it's a gunshot to the head. But something. Something to relieve the pressures of their everyday life, like having to tie their shoes.
this "They Are Humans" bit..
I believe the T-3000 wants a word..
enough of the niceties: time for the eye-gouging..
and yes, I probably *should* be asleep right now!
by mightymike D on Dec 10, 2011 3:15 PM CST up reply actions
This whole concept is like Abstract Geometry.
It’s basic tenet is that two parallel lines meet at infinity.
My serenity is inversely proportional to my expectations.
LET’S GO YOU WHITE SOX!!!!!
OT.. but no Moarning Links, so..
I’m thinking of watching San Jose/St. Louis in the "Battle Of How We Spell ‘Saint’ " tonight.. partly to check out how fearsome those Sha-arks are looking ahead of Sunday and partly to see the Blues get their heads kicked in..
enough of the niceties: time for the eye-gouging..
and yes, I probably *should* be asleep right now!
Speaking of SJ, Emery is definitely starting.
"Well now you're just talking like Foghorn Leghorn!"
by justforkicks on Dec 10, 2011 5:14 PM CST up reply actions
yeah, read that..
I’m not too bothered, either way
enough of the niceties: time for the eye-gouging..
and yes, I probably *should* be asleep right now!
by mightymike D on Dec 10, 2011 5:24 PM CST up reply actions
As long as we win I don't care. At least Crow will get to actually sit with the team on the bench this time!
so many games on tonight at the same time =(
"Well now you're just talking like Foghorn Leghorn!"
by justforkicks on Dec 10, 2011 6:04 PM CST up reply actions
he looked so isolated and sad at the Isles game!
enough of the niceties: time for the eye-gouging..
and yes, I probably *should* be asleep right now!
by mightymike D on Dec 10, 2011 6:20 PM CST up reply actions
OT oh so very much (its quiet here tonight)
but on the UK X Factor tonight (no I don’t watch it) Leona Lewis covered NIN ‘Hurt’… which was also famously covered by Johnny cash not long before his death.. and the video to the Man In Black’s version is still the most powerful music video I’ve ever seen.. it must have been quite dusty in the room when I saw it for the first time, because my eyes started watering..
So now we get the Karaoke Sauron’s puppet’s version…
I am anger!
enough of the niceties: time for the eye-gouging..
and yes, I probably *should* be asleep right now!
I know what you mean,
I just rewatched the music video- must be dusty down here in U of I’s library as well or else finals are just really getting to me.
I saw this comment on youtube of a quote from Reznor on the video, “I pop the video in, and wow … Tears welling, silence, goose-bumps … Wow. [I felt like] I just lost my girlfriend, because that song isn’t mine anymore.”
..pretty cool
I basically don't really understand these stats, but its still very intersesting
Thanks CNS for the great post, and to everyone trying to clarify it in the comments!
"Well now you're just talking like Foghorn Leghorn!"
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