Face-Offs

We all know that face-offs are important. Win the draw back to the point in the other team’s end and you’ve got a quick shot on goal. Lose the draw and the other team can regroup and break out or ice the puck. But how do we quantify the value of winning or losing a face-off?

Using the NHL’s Real-Time Scoring System (RTSS), we can determine what happens after a face-off is taken. In particular, we can determine how winning or losing a face-off makes it more or less likely that a team will score or get scored on. The majority of NHL face-offs are taken from the nine official face-off dots, with a small percentage taken at the location of the play that resulted in the stoppage in play, which is rarely a significant distance from the regular face-off locations.

Unfortunately, the publicly-available RTSS stats report only the zone that the face-off took place in: offensive, neutral and defensive. Using only those three zones, we will make the following assumptions:

- Draws taken in the offensive end are all approximately the same, regardless of which side of the ice they’re taken on, or whether they occur at the face-off dot, or at the top of the face-off circle.

- By symmetry, the same is true of defensive zone face-offs.

- This is not true of neutral zone drops – face-offs at center ice are at a much more neutral location than when the puck is dropped just outside one or the other blue line. We can separate the center-ice face-offs from the rest (since most occur at the start of a period or after a goal) but we are unable to determine which end the others occur at. For simplicity, all neutral zone face-offs will be grouped together.

The metric we will use for evaluating the significance of winning or losing the face-off is ‘goals allowed per face-off’. The cumulative goals allowed per 100 neutral zone and center-ice face-offs is shown in the chart below.

There is a slight disadvantage to losing these neutral zone face-offs, on the order of 30% over the first thirty seconds. This is not surprising since losing a face-off just outside your own blue line can easily result in an odd-man rush inside your own zone. But how does the probability of being scored on change over time after a faceoff?

By plotting the rate of goal scoring over time, we can see how winning or losing a face-off affects the likelihood of a team getting scored on, and for how long this effect lasts. This figure shows the rate of team goals allowed following a neutral zone face-off (which includes center-ice face-offs):

Initially, there is a disadvantage to losing these face-offs, but after approximately 25 seconds, the rate of goal scoring seems to be independent of the outcome of the draw, converging to the NHL aggregate of 0.07 goals allowed per 100 face-offs per second.

Compare this to what happens for a face-off taken in a team’s defensive zone:

In this case, the outcome is much more significant. In the first seven seconds after a face-off in your own end, you are 10 times more likely to be scored on if you lost the draw than if you won it. In fact, more than 10% of all the goals in the NHL during the 2003-04 season were allowed within 20 seconds of a team losing a face-off in its own defensive zone. Overall, that means that one out of every 40 lost face-offs resulted in a goal in the next 20 seconds. In a league where teams score just 2.5 goals per game, that makes a significant difference. At the other end of the ice, it’s not such a big deal:

Winning or losing a face-off in the offensive zone has little effect on how likely you are to get scored on. This isn’t surprising since it takes a team at least seven seconds to get down the ice and score, and a lot has to happen in those seven seconds – several players need to be beaten, and this isn’t any more or less likely to happen whether your team is controlling the puck at the blue line or if the other team has the puck behind their own net. The number of goals allowed in the first 12 seconds after the draw is actually higher if you win it than lose it, likely because a draw back to the point can be stolen by the defending team and taken for a breakaway. But overall, having a face-off in your opponent’s end is a positive offensive situation, and your goals allowed rate takes quite a while to reach nominal levels.

Implications

The most significant result of this analysis is that teams should use their best face-off men on face-offs deep in their own end to decrease the likelihood of being scored on. Similarly, they should also use their best face-offs takers in the offensive zone. If a team improves its face-off winning percentage in these situations from 50% to 60% (say, by signing Yanic Perreault, assuming all other things are equal), it can expect, on average, to improve its goal differential by 25 goals over the course of the season. In today’s NHL, this translates into an additional three or four wins, which is obviously an advantage any team would take.