[corporatejay]

Originally Posted by delayedreflex

Agreed - the paper extrapolates existing data, where the bulk of the dataset likely comes from 6 on 5 play in the last 2 minutes of the game. The paper assumes 1.18% chance for the team with the pulled goalie to score per 10 seconds, vs 2.58% chance for the team who is up by a goal. However, the team who is up by 1 is likely playing more conservatively in the last 2 minutes, simply trying not to concede a goal - so likely, if there was more time on the clock, the % of scoring would go up (both by the team with a pulled goalie, and by the team who is up). By the paper's own acknowledgement, the higher the scoring probability, the shorter the optimal window. So I don't know if the data can be extrapolated like the authors are doing in this paper.

Still, the general idea might be sound (coaches don't pull goalies as early as they should) even if the specific numbers are off. Pulling your goalie earlier will almost definitely hurt your team's goal differential, which is going to make your team look worse - but if you win one more game per year by pulling your goalie earlier, while losing three more games by 2 goals instead of 1, it is technically worth it. Patrick Roy did seem to see some success with earlier goalie pulls in his tenure, but I doubt it was a big enough sample size for us to see whether the strategy compared favourably with more conventional wisdom.

I always found it weird that teams don't pull their goalie when they have a PP with less than 10 minutes left. That's likely your best chance to score.