Wednesday, July 02, 2008

On Devin Hester

I haven't talked about this much here, but living in the Chicago area and being a fan of a team other than the Bears, I'm sick and tired of hearing about Devin Hester, and how good he is. I'm not trying to deny that he's a very good return man, but he's not nearly as good as Bears fans think he is. The latest to-do start when I claimed at lunch that Josh Cribbs was at least as good at returning kicks as Hester was last year. Many electrons have since been spilled on the issue, but here's the original email from the argument, suitably adjusted into a blog post.

On my part, this argument that Cribbs was at least as good as Hester had at its root this recent analysis by PFR blog. From PFR, here are the top 50 individual kickoff returner seasons since the merger. This is the entry at the top of the list:

kr kryd krtd AY/KR LGKR KR_VAL year team
59 1809 2 31.00 22.77 486 2007 cle Josh Cribbs

Quoting PFR:
Josh Cribbs’ 2007 season was truly remarkable. He added 486 more adjusted yards than the league average kickoff returner would have produced, and another 136 adjusted yards above what the league average punt returner would have compiled with the same number of returns.


One of the argument to which I was responding was that this inflates Cribbs' value because he had more kickoff returns than Hester. Yes, it is true that Cribbs had more returns than Hester. But it's harder to be above average with more returns than with fewer returns. That he had fewer TDs, but more yards, is also a sign of consistent goodness-because touchdown returns tend to be non-normally distributed, having a better return average with fewer return TDs is a sign that Cribbs didn't fluctuate between good and bad returns, but was instead more consistently good.

Ah, you say, PFR's system doesn't take into account field position. Very well, then, let's use a system that does. Football Outsiders' DVOA is designed to take field position and game situation into account. They don't break out player ratings, simply because there's not enough good data to do so, but they do have team data on kickoff returns:
CLE Kickoff Return: 31.2 (1st in NFL)
CHI Kickoff Return: 14.1 (4th, also behind HOU and NYJ)

I'd also point out that Cribbs had the misfortune of playing on a team that actually had an offense, so you'd tend to expect the Bears to end up with better field position. Cribbs, alas, made teams pay for their temerity to try to pin the Browns deep.

Oh, and as to judging returners solely or primarily by how many touchdowns they score, I refer you to this post from the baseball context on statistics.

Mind you, the point of this is not necessarily to declare Josh Cribbs a superior kick returner to Hester in 2007; after all, they played on different teams, with different teammates, and in different situations. It is possible that Hester on the Browns would have done well and Cribbs on the Bears wouldn't do well, or vice versa (Hester was not a particularly good returner his last year, especially, at Miami, after all). But, that Devin Hester was the best kickoff returner in the NFL in 2007 is not at all a clear proposition.

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More content coming later.

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