Thursday, November 4, 2010

Power Ranger or Texas-Sized Bust?

So . . . a belated and bitter congratulations to the world-champion San Francisco Giants (bitter because back when I used to follow baseball the Rangers were "my" team).  They handled the Texas Rangers very adeptly en route to a 4-1 World Series win.  One of the biggest surprises was that supposed playoff ace Cliff Lee of the Rangers had two losses in the series, after having never lost a playoff game before.  On why the notion of a "playoff performer" is a fallacy after the jump.

Sportscasters bug me; sometimes it is the inane comments they make (example from last nights Celtics-Bucks game: "I always tell coaches not to worry even if the other team's best free throw shooter is at the line, because you'd be surprised how many times he splits the pair of free throws," - thanks, but I'm not surprised if a 90% shooter misses one of two every five times or so, genius) but mostly it's the attributions.  A player does something great or horrible, and the sports reporters go into overdrive to determine what caused it.  One player shrinks in the playoffs, another rises.  One player "really wants to win" and another "doesn't have his head in the game."  Too much explanation, not enough consideration of the role of randomness in sports.

This baseball playoff gave us a few examples, none greater than Cliff Lee, the ace pitcher of the Texas Rangers.  Coming into this year's playoffs he had a 4-0 record over five games, with better stats overall than he had otherwise in his career.  And in the first two rounds of the playoffs he bolstered his playoff-performer image, winning all three games he pitched. 

Naturally all of the commentary was on how he rose to the occasion in the playoffs and thrived under the pressure.  But then an odd thing happened - he pitched poorly in the World Series.  This left the announcers with a few choices for explanation: maybe he shrunk under the greater pressure of the World Series (unlikely - had pitched in a World Series before); he simply had an off game or two (I suppose it's possible) or maybe, just maybe, he was pitching how he usually pitched!  Maybe the 8 preceding games were just a lucky situation wherein he had good games in big-game situations. 

Sports performance is not constant; there is variability.  A pitcher with an earned-run average of 3.00 doesn't give up three runs in each and every nine innings he pitches; he does so, on average, over a longer period.  During that period there may be good and bad stretches.  Considering the vast number of pitchers who have played in the playoffs, is it not possible that some of them were just lucky to have a good stretch in those games?  It absolutely is.

The flip-side of this is when someone performs poorly in the playoffs (I'm talking to you, A-Roid).  Alex Rodriguez has a unfair reputation as someone who does not perform in the playoffs, but when you look at his stats in those games compared with his regular season performance, they aren't that different.  He had a bad run in 2005 and 2006, but apart from that, he met and sometimes exceeded his regular-season numbers.  But because he was unlucky, he is branded as a playoff bust.

But hey, if you can capitalize on a lucky set of games, why not.  Jerome James played the only good basketball of his career in the 2005 playoffs and was rewarded with a $30 million contract (though it was from Isiah Thomas, who ruined the Knicks for a generation, but I'll rant about that another time).  Chauncey Billups hit a few big shots in the playoffs, earned the name "Mr. Big Shot," and now it doesn't matter how many shots he bricks in the postseason, he has a positive big-game image. 

The other story from this baseball postseason is Roy Halladay's no-hitter in his first postseason game.  Congrats, Roy, you're now a playoff hero forever.  Let's ignore your other two playoff games, which brought your postseason ERA to 2.45 (regular season: 2.44), your strikeouts per nine innings to 8.3 (regular season: 7.9) and your home runs per nine innings to 0.8 (regular season: 0.9).  Forget that variable inputs tend to regress to the mean - let's just think about the no-hitter and selectively remember that.

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