Puck possession helps predict playoff chances, analytics suggest

Springtime means different things in different NHL cities. In some cities, fans can begin to get comfortable with their shiny new trade deadline acquisitions – players intended to help them on their way to Lord Stanley’s coveted mug. In other cities, fans brace themselves for the inevitable end to the 18-wheeler’s freefall, and hope that Connor McDavid might emerge from the wreckage of the season.

In other cities still, spring means the excitement of a playoff race, with uncertain outcomes but with at least some hope of making the league’s second season.  For those teams on the outside looking in, the question is: how can we tell whether that hope is reasonable, or the fanciful dreaming of a pretender?

In the last 6 full seasons (so 2007-08 to last year, but not counting 2012-13), there have been 10 teams who made the playoffs even though they did not hold at least a share of a playoff berth after 60 games.

What, if anything, do these late season comebacks (and corresponding collapses for teams that lost their tickets to the big dance) have in common?

Typically, the comeback teams were better possession teams than the collapsing teams. The average Score Adjusted Corsi, or SAC, of the comeback teams was 50.2, while the average SAC of collapsing teams was 47.7. Indeed, only 3 of the comeback teams caught teams that were better in terms of SAC.

This should not be too surprising. As many studies have demonstrated, possession metrics aren’t perfect, but they do pretty well at predicting a team’s future record. Moreover, in this case, we’re talking about teams that have roughly the same number of points over the first 60 games.

If a poor possession team has generated the same record as a good possession team over the first 60 games, who seems more likely to be able to step up their play down the stretch? A team that’s built their record on goaltending and shooting probably doesn’t have much room to go up in those categories, and it’s very rare for a team to suddenly start generating more shots. A good possession team, meanwhile, must not have had as good goaltending or shooting (or else they would have had a better record), and so is more likely to have room to improve their play in those areas. (There are exceptions for sure. For example, a team could have a great goalie who is only pretty good in the first part of the season and off the charts good down the stretch.)

Looking at this year’s situation, there don’t appear to be any prime comeback candidates. In the East, after 60 games the number 8 spot was occupied by Boston -- a pretty solid possession team, with a 52.3% SAC. Florida, Ottawa, and Philadelphia aren’t terrible (at 50.3, 50.1, and 49.4 respectively), but there isn’t much to suggest that they can catch a Boston team that is just now getting healthy.

In the West, while there may appear to be more of a race, chances are it won’t pan out to be much of one. The two wild card teams after 60 games were Winnipeg and Minnesota, both very strong possession teams. The chasers right now are Calgary, one of the league’s worst possession teams with a SAC of 44.4%, and San Jose, whose SAC of 51.1 is not bad, but considerably lower than their 54.6 of a year ago. The two teams that were just ahead of the wildcards were Los Angeles and Vancouver, both of whom could be catchable based on the point difference between them and Calgary and San Jose. The Kings, however, own the league’s 2nd best SAC (at 54.4%) and appear to be turning things around. That leaves the Canucks, whose SAC of 49.4% is less than San Jose’s, but they also had a 5 point cushion after 60 games.

Of course, this isn’t to say that it’s impossible for some team to come from outside to claim a playoff berth, just that it’s unlikely. But it sure would make things more interesting if some team were to pull it off.


Comeback Team Points Out of Last Playoff Position Score Adjusted Corsi Teams Caught Score Adjusted Corsi
2007-08 Colorado 3 47.8 Vancouver 47.6
2007-08 Washington 3 55.2 Buffalo 49.5
2008-09 Anaheim 4 51 Dallas 49.4
2008-09 St. Louis 5 47.8 Edmonton 47.7
Minnesota 47.7
2008-09 Carolina 3 52.3 Buffalo 47.9
2008-09 Pittsburgh 4 46.6 Florida 47.2
2010-11 Buffalo 1 50.8 Carolina 48.2
2011-12 Los Angeles 1 53.2 Calgary 46.9
2011-12 Washington 2 47.7 Toronto 49
2013-14 Columbus 1 49.8 Toronto 43.6
Average Score Adjusted Corsi 50.22 47.7


  1. Gord's Gravatar Gord
    March 8, 2015    

    Looking for stats on PP(puck possession) by period and GF & GA by period seems to run counter to overall PP scores although no in depth analysis on my part
    Teams that bring it on in 2nd,. and 3rd. So any analytics based on that stat?

    • Phil Curry's Gravatar Phil Curry
      March 11, 2015    

      The best analytics in the spirit of what you're talking about are score adjusted PP measures. It has been noted by many that teams turn it on when down (especially in the 3rd period), and so it isn't unusual for losing teams to have better possession numbers than their opponents. Score adjusted Corsi (for example) takes this into consideration and gives an idea of which teams are good at rallying when down and also keeping the pressure on when they're ahead. The site I use to get Score Adjusted measures of possession is puckon.net. If you follow the link, there's an explanation of it, along with a link to Eric Tulsky's original work that developed this stat.

  2. Chris MacDonald's Gravatar Chris MacDonald
    March 9, 2015    

    It would be interesting to see if the possesion trend has changed from the season average compared to the past 10 games or since the All Star break to see if there is a shift in play. Could a team like Ottawa have increased their possesion percentage and now show a trend that would make them potentially playoff bound.

    • Phil Curry's Gravatar Phil Curry
      March 11, 2015    

      Hi Chris, and thanks for the comment.

      I agree it would be interesting to see if teams are currently playing better than there season average. This can be a tricky thing, however. Possession can fluctuate over the course of a 10 game span (although perhaps not as much as shooting or save percentage), and so it might be difficult to tell if increased possession is due to these random fluctuations or if something has actually changed in a more permanent fashion. Having a couple of games against Buffalo, for example, could lead to a team's 10-game average being higher than their season average. On the flip side, things like coaching changes or the return of key players from injury could perhaps be indicative of a more permanent change, for example. Otherwise, you'd probably have to break down some game tape to see if there really is something different about how a team is playing that's leading to their improved possession numbers. Hopefully, data on the micro aspects of the game will be available soon as the NHL implements some form of tracking technology!

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