We have analytics for just about every measurable, statistical category in the NHL nowadays, and if you’ve ever been curious about the success rates on coach’s challenges, we now have data available for that as well.
On Christmas day, hockey analyst Prashanth Iyer of MetaHockey put out a really cool and intriguing set of data on individual coaches around the league and their success rate on the specific calls they challenge.
Merry Christmas, I did a hockey thing:— Prashanth Iyer (@iyer_prashanth) December 25, 2018
How good is your coach with the challenge? pic.twitter.com/0KdjFhr1bX
For more context, Iyer also provided it in a plus-minus viewpoint as well.
The glaring theme here, as dictated by the color key on the side of the graph, is that a coaching staff who challenges the fewest amount of times ends up with better results. That could simply be due to the fact that with less challenge attempts, you have a higher chance of your percentage being greater if you end up being correct and overturning a call — not necessarily that you understand the rule better than the referees who missed it. In the same vein, it could also highlight how much more risk adverse those coaching staff members are.
Overall, Canucks’ head coach Travis Green leads the way with a 70 percent success rate across the board, which is pretty impressive. He’s either very lucky, or he picks his challenges wisely.
Former Colorado coach Patrick Roy on the other hand contradicts that theory with very few challenge attempts that didn’t pan out.
When it comes to Penguins’ head coach Mike Sullivan, he makes his money at a middle-of-the-road rate, roughly winning 35 percent of the 25 to 30 or so challenges he’s made from 2015 to now. As noted by his coloration, Sullivan and his staff like to challenge calls often, which may skew their final results a bit.
Iyer also broke down the data he collected even further into offsides and goaltender interference calls and the success rates of coaches in those specific instances.
Here's what happens if you split it out by goaltender interference and offsides.— Prashanth Iyer (@iyer_prashanth) December 25, 2018
Jared Bednar actually knows what goaltender interference is pic.twitter.com/BLOXNhgCCz
Avalanche head coach Jared Bednar is seemingly one of the few people in the entire sport who knows what goaltender inference actually is. The rest of the league... not so much. Sullivan, once again, is hovering around a 30 percent mark.
As for offsides, team replay coaches behind the bench clearly have a good grasp on when to attempt to overturn incorrect calls. Sullivan jumps up to a more than 40 percent success rate with his offsides challenges.
What Iyer then pointed out was how much a team will back off challenging calls if they lost them and the effects of the penalty they received for failing.
Another interesting thing is that you can see the effect of the penalty for a failed offsides challenge (went into effect for 2017-2018) on the team's willingness to challenge pic.twitter.com/X9IU7nR7Wu— Prashanth Iyer (@iyer_prashanth) December 25, 2018
This data is mostly just something fun to take a look at, rather than analyze. With how arbitrary certain calls on the ice are (looking at you goaltender interference), it’s interesting to see just how often coach’s challenges succeed and what teams are benefitting from them the most.