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Impact of Winning an Offensive Zone Faceoff, Even-Strength vs Power-Play

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I got a number of questions about the impact of winning and losing offensive zone faceoffs. The way to think about this is to look at the shot rates in the time following a faceoff:

Shot_rates_post_faceoff_medium

In the long-run, shot rates ultimately converge regardless of whether the faceoff is won or lost. Obviously even-strength shot rate differential converges to zero, while on the PP it is strongly positive for the team with the man-advantage.

It's interesting to see that the peak shot rate is higher at even-strength than on the PP. Just a guess, but a PP faceoff win allows a team to set up in the offensive zone and work the puck around for a better shot. At even-strength, teams are much more likely to win the draw back to the point and blast the puck at the net, hoping for a screen or a deflection.

Here's the shot differential for faceoff wins vs losses at even-strength and on the power-play:

Shot_rates_post_faceoff_delta_medium

For even-strength faceoffs, all we need to go is integrate the area under the blue curve and multiply by EV shooting percentage, which is 5.97%. This gives us a goal differential of +2.45 goals per 100 extra faceoff wins, or 245 faceoffs per two points in the standings. (Incidentally, a neutral zone faceoff is worth +0.9 goals per 100 extra faceoff wins, or two points in the standings per 657 extra faceoff wins.)

On the PP, the story is slightly different due to the asymmetry of shooting percentages:

Win: shots for = 1.332; shots against = 0.200

Loss: shots for = 0.938; shots against = 0.216

On the PP, the shooting percentage for shots for is 8.98%, while it's 7.21% for shots against. That gives us +3.66 goals per 100 faceoff extra wins.

This tells us that a team needs to win 164 additional power-play or penalty-kill faceoffs to get one additional win. But a team typically only takes 790 such faceoffs per season, so it would be virtually impossible to win 164 more faceoffs. On the other hand, teams typically take 2200 even-strength faceoffs in the offensive or defensive zone per game year (remember that the offensive zone result is symmetric in the defensive zone) so it is much more likely that a team could win 245 additional faceoffs.