Goalie impact
Goals saved against the shots a goalie actually faced, ranked per 60 minutes.
How it works
Give each shot its own expectation
Every unblocked shot gets a probability of going in based on distance, angle, shot type, rebound, rush and strength. Add those probabilities and you have expected goals. Subtract the goals allowed to get goals saved.
Weight the difficult circumstances
Deflections and tips count at 50%, rebounds at 50%, and penalty-kill shots at 30%. The ranking is per 60 minutes, so more time in net does not automatically mean a higher rank.
Be patient with the ranking
The split-half reliability is 0.22. It takes about 3,100 weighted attempts before half the number is skill. Early results describe who has played well; they are much less certain about who will keep playing well.
The formula
The formula
Goals saved = expected goals − goals allowed, using the shot weights. Goals saved per 60 = weighted goals saved ÷ minutes played × 60.
Weights: deflections/tips 50%; rebounds 50%; penalty-kill shots 30%. Shot probability uses distance, angle, shot type, rebound, rush and strength.
How we tested it
| Check | Finding |
|---|---|
| Split-half reliability | 0.22 |
| Half the number is skill | About 3,100 weighted attempts |
Split-half reliability asks how well performance in one half of a sample lines up with the other. This result calls for patience.
What does correlation mean?
Correlation, written as r, describes how closely two sets of results move together. A stronger positive relationship means better results in one tend to go with better results in the other. A value near zero means little relationship. It is not a percentage of predictions that were correct.
What it can't tell you
A small sample cannot settle a goalie's true ability. Shot difficulty and weighting help frame the performance, but the rating remains noisy.