How important are backups during the playoffs?
Less than you might think, given the playoff storylines to date.
How Much Are Backups Relied Upon in the Stanley Cup Playoffs?
The Study: After seeing the number of backups playing in these Stanley Cup Playoffs, we were wondering: On average, how much do teams rely on backup Goaltenders during the postseason? While we know that they’re quite effective during the Regular Season, are they equally effective during the Playoffs? And is the difference between starters and backups small enough to make backups worthy of more Playoff ice time?
To answer these questions, we looked at Playoff statistics for Goaltenders from 2013-14 to 2018-19. In this study, the starter for each team was again defined as the Goaltender who had the most starts during the Regular Season. In the case of starters who were traded to a Playoff team, they were reassigned with the rest to the “backup” category. To us, this made sense given that the original starter would have been most responsible for getting their team to the Playoffs.
The Results: In total, 156 Goaltenders played in Games during the time period examined, with 88 of them being starters. Note that these numbers entail treating each Season as a separate goalie (e.g. Andrei Vasilevskiy from 2017-18 and 2018-19 are two separate Goaltenders) given that goalies enter and exit each year, change from backup to starter, etc. In any case, this means that each team played, on average, 1.63 Goaltenders each postseason.
Of 1,062 Games Started (GS), 862 (81.2%) were assigned to starters and 200 (18.8%) were assigned to backups. However, note that starters played in a smaller proportion of minutes (876:32:57 Time on Ice [TOI] or 79.7% of all minutes) when compared to their starts.
Starters had a higher Winning Percentage—at 50.6%—than backups—at 47.5%. They also had a higher Save Percentage—.918 versus .911. That said, note that backups faced a higher percentage of shots (21.6%) when compared to their representation in GS (18.8%) and TOI (20.3%).
Finally, it was discovered that starters were pulled in 7.4% of their GS, while backups were pulled in 9.0%.
Discussion: The results of this study paint a very clear picture. First, starters unsurprisingly performed better across the board. After all, it’s typically the best starting goalies who make it to the Playoffs to begin with. Therefore, what we conclude from the data is that even if a team loses a couple of Games in a row, is down in a series, or has had to pull the starter in any number of games, on average, it’s a smarter decision to stick with the starter.
Second and as a result of our first point, it’s probably better to pull your starter when your team can’t conceivably come back in a game. That way, they can avoid injury and be better rested to win the next game, which will likely be more crucial to the team’s postseason success. While this strategy should be clearly communicated to the starter so as to avoid any negative psychological effects, if our first recommendation is followed, they shouldn’t be bothered anyway since they’ll know that you’re sticking with them no matter what. This appears to be the strategy of New York Rangers’ Head Coach, Gerard Gallant, with Igor Shesterkin.
Combined and in conclusion, the Playoffs are when a team should be leaning on its starter the most. While a Coach has no option but to go with their backup in the case of injury, in all other cases, they should definitely be sticking with their starter.