Lehtonen's Rebound Control

Over on the Smirkin Chicken the poster Clambake pointed out that Kari Lehtonen faces more shots per minute of ice time so far this season than either Pavelec or Hedberg. Clambake concludes: To me, that suggests that Lehtonen is giving up more rebounds. Had he faced shots at Hedberg's clip, he would have faced 100 fewer shots so far (2.13/game), which works out to 8 fewer goals for the season.

I found this pretty interesting. Now it is possible it is just a fluky random thing and Lehtonen has simply been unlucky this year in terms of starting on nights when the team has played especially poorly. If it is just random bad luck then it is unlikely to be present in other seasons, so let's take a look.

Shots Faced Per Minute Played
2005-06
.518 Lehtonen
.485 Other Thrasher goalies

2006-07
.527 Lehtonen
.473 Other Thrasher goalies

2007-08
.578 Lehtonen
.534 Other Thrasher goalies

OK, the data indicates that this a "real trend" since it is consistent over three season. I must admit I'm a bit surprised to see this much of a difference. Now I will say that it is possible that Kari gets the starts against all the tougher teams as the team's #1 but I seem to recall Moose facing his share of tough opponents. The "strength of opponent" hypothesis by using an Expected Shots per Opponent framework to see if Lehtonen happens to face teams that shoot more but at the moment I'm too busy for that, but maybe this summer I can work it up. My expectation is that this pattern can't all be explained by the opposition.

So for the moment let's accept the argument that Kari's rebound control is below average. If that is true how much of a difference is it making? If we calculate the "extra" shots Kari has faced and assume a league average 10% shooting percentage, the numbers suggest that the higher shot differential has led to 7 extra goals against in 2005-06, 21 extra goals in 2006-07 and 12 extra goals against in 2007-08.

How much of a difference would that have made in the standings? Using the Pythagorean ratio which predicts non-shootout winning percentage very accurately, I estimate that it cost the Thrashers 2 standing points in 2005-06, 8 standings points in 2006-07 and 3 standings points in 2007-2008. The first two years are rather significant differences. If the team have finished two points higher they might have made the playoffs in 05-06 and the extra 8 points in 2006-07 might have meant that they don't need to make all those trades at the deadline. This season the team is so bad that the extra three points simply don't matter.

Conclusion: Until I plug in the strength of schedule numbers I'm still not completely convinced this differential is all rebound control. On the other hand, something is clearly going on. I will point out that a lower number of shots could also be produced if the defense has less confidence in the netminder and goes crazy trying to block everything. If you have a lot of confidence in your goalie you get out of the way and let him stop it--he's wearing more padding.

One last thought--it Lehtonen is more prone to rebounds than other goalies, this is something the Thrashers ought to keep in mind when going after free agents. Get out the game tapes and look at which UFA defensemen are great at marking their opponents near the net so opposing forwards don't have a lot of time to put home the loose pucks. Those sort of defensemen could be especially valuable.