The other day, over at my hockey analytics blog, I wrote an article on the relationship between Possession/Corsi (CF%) and Shooting Percentage (Sh%) in 5v5 close situations.
I figured I’d piggy back on that analysis a little and take a look at the Leafs over the past three and a half seasons spanning the Randy Carlyle era.
In my HockeyAnalysis.com article, I showed that, while some elite level teams or truly bad teams can break the trend, there is generally a strong negative correlation between a teams CF% and shooting percentage. Recall that CF% stands for Corsi For Percentage, which is the percentage of all shot attempts taken, for and against, that the team itself took (or shot attempts for divided by shot attempts for plus shot attempts against). So, what this is saying is that better possession teams generally take a hit in terms of shooting percentage. There are some teams that are reasonably good at both (Pittsburgh, Chicago) and there are some teams that are terrible at both (Buffalo), but generally speaking good Corsi teams are weak shooting percentage teams.
I wanted to take a look at how Corsi and shooting percentage compared during the Randy Carlyle era, so I produced the following chart to show just that.
The chart above is for the past 4 1/2 seasons using all 5v5 data up through Saturday’s game against the St. Louis Blues. The black lines denote breaks between seasons, the red line shows when Carlyle was hired, and the green shows when he was fired. This is a rolling average of 1000 Corsi (for and against) events.
There is in fact a weak negative correlation between the two statistics (correlation is -0.24) which supports my previous findings. It should be noted that there has been fairly significant roster turnover during this time (Grabovski, MacArthur, Kulemin, etc., out, Clarkson, JVR, Winnik, Santorelli, etc., in) so the correlation may not be as strong as if there were more roster stability.
Here is a summary of the last 4 1/2 seasons pre-Carlyle, under Carlyle and post-Carlyle.
Everything points to the Leafs being a weaker Corsi team under Carlyle but a better shooting percentage team. When Carlyle took over, the team’s CF% immediately started dropping and their shooting percentage immediately started improving. The Leafs shooting percentage dropped off last year from 2012-13 levels, but that is likely a result of losing good on-ice shooting percentage players in Grabovski and MacArthur. The Leafs have also been a significantly better possession teams under Peter Horachek and their shooting percentage has tanked. Yes, the sample size is incredibly small and a 3.6% shooting percentage is unusually low, but one should probably not expect it to rise back to Randy Carlyle levels. All evidence suggests if the Leafs improve their possession game it will come at the cost of shooting percentage. The hope is the improved possession game results in more consistency and provides more benefit than the cost of the hit to shooting percentage, but Leaf fans might want to get used to more low scoring games like we have seen the past week or so. What it also means is that real significant improvement will likely require roster changes, not just coaching and playing style changes.