How much did the Blackhawks’ blue line struggle in the 2017-18 season?

Chicago’s opponents had high-quality scoring opportunities all too often this winter.

We’ve already covered a few aspects of the Chicago Blackhawks dismal 2017-18 season. The special teams were bad and the Blackhawks’ goaltending issues didn’t help matters. And at even strength, the players directly in front of Chicago’s net didn’t have their best performances, either, and that’s the focus on this Friday afternoon.

The Chicago defense corps had a difficult time containing opposing offenses all season.

There were 256 goals scored against the Blackhawks this season, putting them in a three-way tie with the Carolina Hurricanes and Arizona Coyotes for the eighth-highest total in the league. Just one season ago, Chicago only allowed 213 goals, 10th-best in the league. Of course, Corey Crawford played that whole season and made a huge difference. But perhaps this season exposed how much the Chicago defense needed Crawford to bail them out in the last few seasons (while simultaneously confirming that Crawford is the best goalie in the Western Conference and maybe even the whole league).

Because a deeper dive into the numbers associated with the Blackhawks defensemen is not a pleasant one. Connor Murphy and Erik Gustafsson were the only players over the team’s CF% level of 52.33%, with Jan Rutta (49.92) and Gustav Forsling (48.91) falling well short. The plus-minus statistic certainly has its flaws, but a minus-29 for Duncan Keith is a horrendous sight for already sore eyes.

The Blackhawks actually finished with the fourth best CF% in the league, which looks great on the surface. But a more detailed look suggests teams got quality over the Blackhawks’ quantity of shot attempts.

Using Natural Stat Trick’s website, I sought out the rate of high-danger chances against per 60 minutes of 5-on-5 hockey, using 500 minutes of 5-on-5 play during the 2017-18 as the minimum threshold, roughly 30-35 games.

Might want to sit down, these numbers aren’t pleasant.

The parameters above yielded a return of 209 NHL players. Out of the 25 players who had the highest rate of HDCA/60, there were five — FIVE!! — Blackhawks: Forsling (13.87, 6th), Brent Seabrook (13.61, 8th), Jan Rutta (13.05, 15th), Duncan Keith (13.04, 17th) and Erik Gustafsson (13.04, 25th). I double and triple-checked to ensure those numbers were correct. We’ve already covered how much the goaltending affected Chicago this season, but the numbers above suggest that they weren’t getting much help from the players in front of them.

(A tiny dose of optimism, albeit in a small sample size: Blake Hillman’s rate was 10.24 in his four games, lower than all of Chicago’s regular blue liners who’ll be back with the team next season and he started in the offensive zone less than half the time. Encouraging signs there.)

There are more statistics out there for additional insight into Chicago’s defensive problems, including this chart from Sean Tierney’s excellent website and this insightful article by Corey Sznajder for The Athletic.

But the overall issue with the Blackhawks defense can be summarized by simply stating that this team surrendered too many quality chances against in each game and, without their No. 1 goaltender there to bail them out, Chicago’s opponent had no problem lighting the lamp against the 2017-18 Blackhawks.