A couple of days ago I wrote about one reason that's been given by fans and media for a team playing below their standard level of ability. In that study I concluded that there is no negative effect on a team in their first game back after a long road trip, and that, if anything, there is a slightly positive effect. That particular myth is not backed up by a sober look at the real wins and losses by actual NHL teams. But what about the effect of playing in back-to-back games? I remember playing two or three games a day in tournaments when I was twelve years old, and while I may have felt tired by the end of that last game, I was twelve and we're talking about professional athletes here. So does playing on back to back nights actually effect the ability of a team or is it yet another aspect of Canadian hockey mythology with no roots in reality?
In order to do this study I only used instances where the second half of the back to back was on the road so that I could use the road record overall as a control. After last night's games there were a total of 188 games where the road team was playing the second half of a back to back. Given that there are only 729 games in total that represents just over 25% of all games. I was shocked that fully a quarter of games are played with the road team on the back half of a back to back.
Anyway, the good news about that is the sample size for this study is probably large enough to come to a conclusion. In the aforementioned 188 games the goal differential (not including shootout goals) for the road team is -124 or -0.660 goals per game. The points percentage of the road team is 44.9% and the winning percentage is 38.8%. In the other 541 road games that teams have played this year the points percentage is 51.1% and the winning percentage is 46.0%.
The difference is huge. In back to back situations teams are much less likely to register points (a difference of 6.2%) and the winning percentage falls dramatically (a difference of 7.2%, the same as the gap between the St. Louis Blues and the Anaheim Ducks). This meme is definitely based in reality which of course leads to the question of why on earth 25% of NHL games are played with the road team at a significant disadvantage. The best answer I can think of is that it makes it more likely for the fans to be sent home happy. Another thing this may point to is a possible effect on playoff games. If there are fewer back to back games in the playoffs the road team has a much better chance to win than they do in the regular season.