PULLING THE GOALIE
CHANGING GOALIE = RESHUFFLING THE DECK CHAIRS
Note that shot volume against the starter is much higher than usual – so when the goalie gets pulled it is certainly partly his team’s fault.
We see two effects here:
1) shot volume against drops significantly – 23%; and
2) shooting percentage actually rises slightly.
a team’s expected goal differential is worse if it changes goalies than if it does nothing.
Now this doesn’t mean that changing goalies is a bad strategy. If your team is losing by 3 goals, the odds of coming back to tie or win is about 10% after the first period, and less than 5% after the second. Is it worth tiring out your goaltender in a game he’s going to lose anyways? Probably not. But a team is reducing its odds of a comeback by putting in the backup – just as surely as it increases its odds of losing the game by starting the backup.
COACHES ARE PULLING THE GOALIE EARLIER THAN EVER
(Oct 2015)
Teams had the best chance to win if they pulled their goalie with about two and a half minutes remaining when down one goal.
OPTIMAL PULL TIMES DEPENDING ON THE SCORE
(Mar 2018)
That immediately shows that pulling the goalie is a negative expected value move in terms of goals
But expected value of goals is not the appropriate criterion. What matters is expected number of standings points.
Optimal Pull Times (time remaining):
Down one goal : 6:10
Down two goals: 13:00
Down three goals: 23:40
Down 4+ goals: pull and keep pulled
The intuition is clear. If the chance of all scoring is much lower, then you have to pull earlier as the “safe is death” logic of pulling the goalie is even stronger because the chance that something happens, and you desperately need something to happen when trailing, is now much smaller if you do nothing.
pulling the goalie actually reduces the risk of losing the game — it’s an insurance move — and this is the proper risk measure
THE STATE OF GOALIE PULLING IN THE NHL
· There isn’t a particularly strong relationship between the strength of a team’s offense and the average time that they pull their goalie.
· Among games with a one-goal deficit, the success rate has been around 15 percent
· Successful outcomes when the trailing team is down by two goals are more rare: about one percent overall
· Successful outcomes tend to start with a slightly more aggressive goalie pull.
PULLING THE GOALIE ON PP
One general result is that teams that are trailing should pull their goaltenders much earlier when awarded with a power-play than when playing 5-on-5.
Interesting academically. Results indicate it is marginally beneficial. But will never ever happen.
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