Monday, October 26, 2009

Cause or Effect?

Kurt Overhardt is Ryan Kesler's agent. Kesler will be a restricted free agent at the end of this season, so Overhardt is working on getting him signed to a fat new extension. And either Overhardt is trying to twist the numbers to make his client look good, or he is simply mixing up cause and effect.

As the Vancouver Province reports based on Overhardt's research, the Vancouver Canucks had a better record last year in games where Ryan Kesler had more ice time than either Daniel or Henrik Sedin. That seems surprising on first glance, considering that the Sedins scored a lot more points than Kesler did and also had much better plus/minus numbers (Daniel +24, Henrik +22, Kesler +8). But when you think about it a bit deeper it seems obvious to me that this has more to do with the relative roles of Kesler and the Sedins than their effectiveness as hockey players.

If Vancouver is winning, who is more likely to be on the ice, their best offensive players or a Selke-nominee who is one of the league's best defensive forwards? Similarly, if the Canucks are behind, is the coach going to turn to Kesler, with his career high of 59 points in a season, or to the Sedins, who have each averaged nearly a point per game since the lockout?

In short, I doubt the Canucks win because Kesler plays a lot, it's more likely that Kesler plays a lot when the Canucks are winning. Or perhaps more precisely, since Kesler usually played more than the Sedins did by virtue of pulling more special teams duty, the Sedins weren't as likely to play big minutes except when the team was losing. Either way, it means that attributing the team's record to Kesler is a big stretch.

Good try by the agent, though. However, Mike Gillis seems like a sharp GM to me so I'm not sure he'll buy that line of argument, even though he no doubt sees the value of a great young two-way player like Kesler and will probably end up finding the necessary resources to eventually get the deal done.

2 comments:

Statman said...

It's like when football commentators remark that a team is more likely to win when they have high rushing yards, so the team should run more.

Not really... teams that are leading in a game have the luxury of running, & if they don't get first downs & points they can punt it away. The team that is behind needs yards & points, & have a limited time to do so, so they pass more & run less. Duh.

R O said...

This is sort of like a hockey version of the baseball sabermetric contradiction of "triples have negative run value", isn't it?

A correlation between two variables (in this case: Kesler TOI vs. Canucks win%) is being taken to mean causation. Well not only does correlation not imply causation, but in this case the correlation doesn't even mean anything because other elementary factors haven't been factored into determining the correlation!

Two layers of laziness - and I wouldn't be surprised if it worked on some GMs.