Advanced stats predict winner of Stanley Cup finals
By Ian Cooper, Phil Curry, IJay Palansky & Mikal Skuterud
Now wasn’t that a fun conference final round? Yeah we’re a little biased given that we’re now getting the Tampa Bay vs. Chicago Stanley Cup finals we predicted six weeks ago. But we don’t think we were the only ones who were having fun here.
As we predicted, Tampa beat the Rangers in seven games. Meanwhile the Ducks, who previously managed an 8-1 record in the playoffs, didn’t exactly wither in the face of their first strong opponent. But their luck did run out against the Blackhawks, with goaltender Frederik Andersen proving himself to be the middling talent we thought he was by giving up a remarkable 19 goals in the final four games of that series.
We had Anaheim losing in six but acknowledged that their improved play toward the end of the season, coupled with Chicago’s depleted blueline, might make this one more competitive. And indeed it was.
As for Andersen, he managed to be perfectly mediocre during five-on-five play, posting a save percentage of .923, which was basically identical to Corey Crawford’s .924 (stats courtesy of war-on-ice.com). But the moment the Hawks had a power play or pulled Crawford for an extra attacker, the guy suddenly looked like the second coming of pretty much any Maple Leafs goalie of the past decade.
Our model gives a lot of weight to a team’s regular season penalty kill when predicting their playoff success, and unfortunately for the Ducks theirs (81%) just wasn’t any good. As a result Anaheim lost despite managing to not get killed by the Hawks on possession and actually outscoring them 17-15 during five-on-five play.
Meanwhile, in the East the Bolts managed to save us from a whole bunch of annoyingly predictable dissertations about how Tampa Bay’s undersized stars just couldn’t handle the physical dominance of New York forwards like Rick Nash, Chris Kreider and Kevin Hayes, and how in today’s NHL, where parity reigns supreme, great defense and goaltending are the keys to winning dull contests that must end by a score of 2–1.
The fact that we’re not all hailing “King” Henrik Lundqvist not only validates our initial prediction back in April that the Bolts and Hawks would be in the finals, it also makes for more entertaining hockey.
So what happens next?
Blackhawks vs Lightning prediction: Lightning in 7
By nearly every measure we consider important these two teams are exceedingly close.
The Lightning secured a few more regular season points (108 vs. 102), and both teams fared significantly better in games won decisively vs. games decided by one goal (where they were both only a shade better than .500). This suggests that, unlike the Ducks, Tampa Bay’s regular season point totals were probably a bit lower than they could have been. Overall, in this series the edge here goes to the Lightning.
Both teams boasted strong regular season penalty kills (83.7% for Tampa vs. 83.4% for Chicago), and while the Lightning posted an impressive regular season score adjusted shot attempt differential during five-on-five play (53.3%) the Blackhawks remained the league’s gold standard when it comes to puck possession, finishing second overall at 54.4% (stats courtesy of www.puckon.net). Slight edge to the Blackhawks here.
Tampa Bay’s got home ice advantage, so that’s some good news for the Lightning. Or is it? Conventional wisdom notwithstanding, the home team has generally fared worse in close series since 2008.
Of course, we now have a bit more information on how these teams have actually played in the playoffs, so perhaps we should look past regular season stats while also acknowledging that different opponents mean this isn’t exactly an apples to apples comparison.
Coming into the conference finals, the Lightning managed a score adjusted shot attempt differential during five-on-five play of only 47.5% for the first two rounds and a score adjusted scoring chance differential of 45.8%. Tampa was often outplayed but won anyway, in large part because there’s a difference between a Stamkos, Johnson, Palat or Kucherov scoring chance (did we mention these guys are good?) vs. one by Montreal’s pop-gun offense.
Great teams that don’t bring their A-game but nevertheless live to fight another day always have the chance of returning to form later on. Such is the luxury of being a great team.
As if on cue, Tampa Bay really seemed to find its stride against the Rangers, who we considered to be their toughest opponent of the postseason so far. Suddenly the team’s numbers improved significantly against the Presidents’ Trophy winners, to a score adjusted shot attempt differential of 51.0% and a score adjusted scoring chance differential of 55.0%. The Lightning not only did a better job of controlling the puck; they also got far more quality chances.
Both the numbers and the eye test tell us the Rangers were lucky to push the series to seven games.
Meanwhile, as many expected, the Blackhawks have been consistently strong throughout the playoffs, posting a score adjusted shot attempt differential during five-on-five play of 51.1% against the Ducks, which was slightly down from their first two round total of 52.5%. But the Blackhawks’ scoring chances were down in the last round, from 50.9% in the first two rounds to 48.6% in the third round (stats courtesy of www.war-on-ice.com).
We don’t want to make too much of this given the small sample size and different opponents. But it’s arguable that the Lightning just played some of their best hockey while the Blackhawks weren’t quite as good last round.
So needless to say we’re thrilled to see him emerge as a Conn Smythe Trophy favorite. But the fact remains the Blackhawks have a depleted blueline and that may explain why the Ducks gave them such a run for their money. A relatively light travel schedule and extra days off in the Cup finals might help, but at some point Tampa Bay, which had the most potent offense in the league during the regular season, may be able to exploit the fatigue.
Back in April our model predicted a Tampa Bay vs. Chicago final with the Lightning having a 52.3% chance of winning the whole thing. With both our teams now in the final, we’re certainly not going to change that prediction now.
We could tell you who Ian’s four-year-old picked, but that would spoil the fun, so click on the link to find out.
The Department of Hockey Analytics employs advanced statistical methods and innovative approaches to better understand the game of hockey. Its three founders are Ian Cooper (@ian_doha), a lawyer, former player agent and Wharton Business School graduate; Dr. Phil Curry (@phil_doha), a professor of economics at the University of Waterloo; and IJay Palansky, a litigator at the law firm of Armstrong Teasdale, former high-stakes professional poker player, and Harvard Law School graduate. Please visit us online at www.depthockeyanalytics.com
Dr. Mikal Skuterud (@mikalskuterud) is a professor of economics at the University of Waterloo.