If Bozak Were Better He'd Get Demoted For Sure

In Phil Kessel and James van Riemsdyk the Toronto Maple Leafs have arguably the most potent pair of first line wingers in the NHL. Last year the two finished 6th and 16th in the league in goals, with a total of 67 between them.


Imagine the damage they could do if they had a bona fide first line centre to play with.


Chris Kunitz has Sidney Crosby. Corey Perry has Ryan Getzlaf. Patrick Sharp has Jonathan Toews. Alex Ovechkin has Nicklas Backstrom. Kessel and van Riemsdyk have . . . Tyler Bozak.


Now unless you’re one of the legion of masochists known as Leafs fans, you’re probably asking “who the heck is Tyler Bozak?”


And if you did, nobody could blame you. To say that Bozak isn’t exactly your prototypical first line centre in the mold of the superstars listed above is like saying that Tim Tebow isn’t exactly Peyton Manning.


Bozak did score 2.32 points per 60 minutes (5-on-5) last year, which was the highest among all Leafs centres. But that’s hardly enough to silence Toronto’s notoriously unforgiving fan base, who insist that Bozak’s really not much more than a passable third-liner who’s managed to hit the jackpot by getting slotted between two of the league’s premier wingmen.


The alternative to Bozak is second line centre Nazem Kadri. Kadri has shown flashes of brilliance in his four-year NHL career, but he’s also spent much of the last few seasons in coach Randy Carlyle’s doghouse because of his defensive lapses and perceived inconsistency.  Kadri scored 1.71 points per 60 minutes (5-on-5) last season.


So which of the two should be the Leafs’ #1 man in the middle?


Under old school thinking, Bozak’s considerably better P/60 would pretty much be the start and end of the discussion. But there are two problems with that approach.


First, because goals happen so infrequently, points may not be an accurate measure of actual performance unless you’re using more than a full season’s data. One way to account for this problem is to measure performance using Corsi For % (CF%) – which is the percentage of all shot attempts by both teams that are taken by a player’s team when he’s on the ice. Because shot attempts happen so much more often than goals, it takes far fewer games for CF% to provide a reasonable measure of performance, and CF% has been shown to be a good predictor of goals over the long run.


Second, regardless of whether P/60 or CF% is used, if we just compare the individual numbers of the two centres the comparison won’t be apples-to-apples because Bozak gets to play with much better linemates. A straight-up comparison of each player’s P/60 or CF% would be measuring (1) whether Bozak playing with Kessel and JVR is better than Kadri playing with second-liners. But what we really want to know is (2) whether Bozak playing with Kessel and JVR is better than Kadri playing with Kessel and JVR.


It turns out that in the 271 minutes Kadri played with Kessel and JVR last season, that line’s CF% was 49.3. In the 831 minutes Bozak played with those wingers, their CF% was only 46.2 (stats courtesy of Progressivehockey.com).


That’s a big difference, and it strongly suggests Kadri is the right man for the job.


Now 271 isn’t a whole lot of minutes, so to double-check my results I expanded the comparison to include every Leaf that Bozak or Kadri played with for 200+ minutes last year.

Bozak vs. Kadri Graph (for website)


As the graph shows, with only a single exception (defenseman Cody Franson) every single Leaf did considerably better when playing with Kadri than with Bozak. In some cases (wingers Joffrey Lupul, David Clakson, Mason Raymond) the differences were astronomical.


This leaves little doubt that Kadri is the better player.

So the conclusion has to be that Kadri should be the first line centre, right?

Ordinarily the answer would be an unequivocal “yes.” But in this particular instance there’s a weird dynamic working in the background. The graph illustrates that definite second-liner Lupul and possible second-liner Clarkson do so much worse with Bozak than Kadri that moving Bozak onto the second line would decimate the second line’s productivity.

This confirms the Bozak-haters’ belief that his success is due much more to his elite wingers than Bozak himself.

But at the same time it cuts the legs out from the anti-Bozak camp’s argument that he should be deposed from the top line. Even though Kadri is clearly the better player, and even though Kessel and van Riemsdyk do considerably better with Kadri, the numbers show that a second line with Bozak in the middle would be so feeble that in the aggregate the top two lines’ production would be much lower.

Ultimately Bozak is lucky he isn’t a better player.  If he were, he’d get demoted for sure.


  1. Ryan Bond's Gravatar Ryan Bond
    November 14, 2014    

    Bozak is a goal scorer, Kadri isn't - or at least he hasn't proven himself to be quite yet. Sure the CF% for all players when Kadri is centre is greater than when Bozak plays the role, but I think you need to take into account the amount of possession each player has on the puck. If Bozak scores more often, CF% will be lower for all other players, especially when his shots are quality ones.

    controlling for puck possession is something that needs to be taken into account here.

    • IJay Palansky's Gravatar IJay Palansky
      November 19, 2014    

      Thanks for the comment, but I'm not sure I fully understand the point. If it's that because Bozak scores there are fewer second chance opportunities, then that's true, but it's also going to be inconsequential to the numbers. It also doesn't explain how players did SO much worse when playing with Bozak. You say "controlling for puck possession" needs to be taken into account. Well . . . it is. The primary metric used is Corsi, which is a proxy for puck possession.

      • May 3, 2016    

        It's great to find an expert who can explian things so well

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