While most pundits are predicting the Washington Capitals to make relatively easy work of the Carolina Hurricanes in the first round of the Stanley Cup Playoffs, there is a clear split between the human commentator community and the advanced-stats community on just how much of a chance the Hurricanes stand against the defending Cup champions.
Yesterday, The Athletic’s Dom Luszczyszyn posted a graphic to Twitter that laid bare the split between the two camps:
2019 NHL first round series probabilities from models, experts, oddsmakers and fans: pic.twitter.com/glPyKEUyvp— dom luszczyszyn (@domluszczyszyn) April 10, 2019
The split is remarkable. Pundits, generally, favor the Capitals by a 2-to-1 margin. But the statistical models say that the series is a tossup, with eight of the 15 favoring the Hurricanes. No other first round series comes anywhere close to this drastic of a split, with the next closest being mainly a question of how badly the Tampa Bay Lightning will steamroll the Columbus Blue Jackets (which may not be a relevant question anymore after last night).
So, what gives? As a Hurricanes fan, can you hang your hat on the stat models that say the Canes have more than a fighting chance?
Over the course of the Hurricanes’ ten-year playoff drought and endless roster turnover, the one thing that has remained a constant in Raleigh is possession domination. The last time the Hurricanes were below league average in Corsi-for percentage was the 2011-12 season. Yes, even the abysmal 30 win 2014-15 Carolina Hurricanes managed to round out the year with a 52.41 CF% — good for ninth-best in the NHL.
The possession domination didn’t lead to favorable results where it counted that season, and the same could be said for the next three years and change. Roster construction certainly had something to do with it. But this season, the Corsi Cup Playoff contenders finally became Stanley Cup Playoff contenders. Now that the team is finally in, we can stop talking about the validity of the shot quantity style of play (although I think that debate can be laid to rest for good now), and start talking about possession and its relationship with playoff success.
The Hurricanes, as a rule, generate a ton of shots on net. That has been the case since 2014 when Bill Peters took over as head coach and now Vice President of Hockey Management and Strategy, Eric Tulsky, came into the fold. “Analytics” as a buzz word has become a hot topic across all major American sports, and hockey is no different. At the forefront of that debate in the NHL is the Corsi statistic.
If one wanted to discount the credibility of Corsi as a measuring stick for competitiveness, they could cite the fact that the Capitals cruised to a Stanley Cup last season with the 24th-best regular season Corsi-for percentage in the NHL, and a playoff CF% ranking ninth out of the 16 playoff teams.
But the truth is that the 2017-18 Capitals were a bit of an anomaly in the possession column. And that’s not to say that winning the Corsi battle wins you hockey games (I would never try to sell you on that as a Carolina Hurricanes fan). Corsi is simply a baseline statistic that measures shot attempts for versus shot attempts against.
It indicates whether or not a team is getting more shots towards the net than their opponent. If you’re shooting the puck more than the opposition, it means that you’re driving possession, and the team that possesses the puck more tends to outscore their opponents. The Capitals defied that norm. But the Capitals aren’t a normal team — they employ a group of some of the best finishers in the NHL, led by arguably the greatest pure goal scorer of all time. I suspect that he had something to do with that.
Since the NHL started tracking Corsi nine seasons ago (or Shot Attempts For, as they call it), the eventual Stanley Cup winner was one of the top two teams in the NHL in CF% at the end of the regular season in five out of those nine years. The Cup winner fell outside of the top half of the league in the metric during the regular season only twice over the nine seasons — last year’s Capitals and the 2016-17 Pittsburgh Penguins.
What this tells me is that modern elite hockey teams generally outshoot their opponents by a wide margin. Of course, it helps that those teams also have some of the best talent in the NHL, hence their Stanley Cup wins. Elite offensive and defensive talent is the key that allows a team to be on the positive end of the possession battle and also capitalize on the increased scoring opportunities. I imagine it as a kind of positive feedback loop.
Goodhart’s law has been commonly expressed by the phrase, “When a measure becomes a target, it ceases to be a good measure.“ This is very applicable when analyzing Corsi in today’s NHL. It’s not a silver bullet, and aiming to win the shot battle on a nightly basis won’t make up for a subpar NHL roster. (Derek Ryan and his regularly-north-of-55% Corsi say hello.)
The bottom line in this is that winning playoff teams almost always post dominant possession statistics. That bodes well for a Hurricanes team that has no problem outshooting their opponent.