During the Winnipeg Jets game against the Los Angeles Kings, Gary Lawless discussed the possibility of certain moves the Jets could potentially make before the deadline.
Lawless mentioned that the Jets were likely done buying rentals, but are still open to “hockey trades” in moving a depth player in exchange for another. One name that came up was Jim Slater.
As a good face off performer, many consider Slater a valuable piece.
Here is why he is not.
Jim Slater has been an effective player on the dot in gaining puck possession. As a Jet Slater has won 54.6 percent of his face offs. He has paced at 57.7 percent this season.
What does this mean in terms of impacting goal differentials? After all, the entire objective in winning face offs is to improve possession, and -in turn- wins.
Not all face off wins are of equal value. The average neutral zone face off at even strength is worth nearly three times less than the in non-neutral zone face offs. A defensive zone face off on the penalty kill is worth about 1.5 face offs for even strength.
The following is Jim Slater’s face offs this season, divided by zone for even strength, and then again for penalty kill situations:
Using the average expected impact on shot differentials, and then average expected shooting percentage, we can estimate the value these face off differentials have in terms of goal differential impact:
Not that much. Overall, this works out to approximately 1.6 goals in improvement over the whole season thus far.
Meanwhile, Jim Slater’s impact on shot attempt differentials has been quite negative. On average Slater’s linemates experience a Corsi percentage drop by 5.9 percentage points when placed with Slater. This is lower than any other Jet with 1000+ 5-on-5 minutes, with the second largest being Chris Thorburn with -4.5 percentage drop.
Since the 2011-12 the Winnipeg Jets have controlled 43.6 per cent of shot attempts with Slater on the ice. This is below 75 percent of fourth-line and depth players in the NHL typically perform.
On average, a player with Slater’s Corsi percentage has a goal differential 1.4 goals lower than the average fourth-line player, 2.4 goals lower than a 50% possession fourth-line player, and 3.6 goals below the top 10 percentile of fourth-line players.
Those numbers are assuming that Slater is a 43.6 Corsi percentage player. Usage-adjusted numbers tend to have Stuart even lower, due to team effects.
In other words, Slater’s impact on goal differentials is essentially washed out by his poor performance in shot-metrics. This also ignores the impact that Slater has been a below-average point producer for a fourth-line player.
Another factor ignored in this evaluation is that winning a face off is only the start of the process. A team winning a defensive zone face off, for example, still needs to break out the puck and gain zone entry on their opponent.
How you attack and defend a face off after it is won or lost matters, as we can see by Slater’s shot metrics post-neutral-zone face off:
Data scraped and graph put together by Muneeb Alam.
The battle over the value of face offs has been an ongoing debate.
Here is the truth:
Face offs matter, just not that much.
While hockey may still be an “eye-test” business, there are somethings the eye-test can never do. Measure and compare a player’s impact on goal differentials due to winning face offs versus their impact on shot metrics is one.
The eye-test can see Jim Slater is a strong face off performer. The eye-test can see that Jim Slater does not drive the play effectively.
When a general manager or scout looks at these two things, they proceed to make judgement call on these two factors by either assuming or guessing which impact outweighs the other. The eye-test cannot do that. Statistics, though, can.