November 26, 2006

Face-offs: Part I

Since I went through the work to calculate this data for Vic Ferrari as a result of comments in this post. I wasn't sure what I was looking for and still don't. The actual coding is a pain as the NHL does not record whether the face-off is even strength or power play so I had to use my standard penalty prediction method to determine when teams are even. Naturally the more complicated it is there's more chance for error, but the results appear reasonable. So all I'm calculating is the probability of a shot and the probability of a goal after a face-off in a offensive zone. There are two situations: a win and a loss, if you lose you can still battle the puck back and get a quick shot off, but obviously the odds of that are much lower.

Using 8 seconds (2005-2006):
Face-offs aren't recorded as EV/PP so I had to use my penalty prediction of PP/EV algorithm.
Even Strength:
win-shot: shots/face-offs = pct%
Win-Shot: 4622/17334 = 26.7%
Win-Goal: 176/17334 = 1.02%
Loss-Shot: 698/17367 = 4%
Loss-Goal: 34/17367 = 0.2%
Power Play offense:
Win-Shot: 1399/5508 = 25.4%
Win-Goal: 74/5508 = 1.34%
Loss-Shot: 195/4460 = 4.4%
Loss-Goal: 4/4460 = 0.31%
Short handed offense:
Win-Shot: 122/616 = 19.8%
Win-Goal: 5/616 = 0.81%
Loss-Shot: 10/806 = 1.2%
Loss-Goal: 0/806 = 0%

It's interesting, but most shots after face-offs are garbage (shooting percentage half of normal).

  • PP face-off win percentage = 55%. (Players who play more PP time will have high win %, PK players will be lower)
  • Shooting is high: ~25%, even though unsuccessful.
  • I hope there are no bugs in these results...
  • The data is poor; it's possible for a shot to be displayed after a face-off even if it occurred before the face-off.

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