Saturday, August 15, 2009

Maybe Stat Zombies Ignored The Marlins But Others Did, Too

The Marlins are actually doing just a bit better than this stat zombie would expect.

From a regression I ran a few years ago,

Winning Pct = .5 + 1.21*OPSDifferential

The Marlins have a .008 differential this year for a .50968 predicted winning percentage. For a 115 games, that would be 58.61 wins. They have 61. So 2.39 more wins than expected. Does not seem like a big deal. The standard error of the regression was 1.54 wins per season. So the Marlins are one win beyond that. We should also wait until the season is over to judge them. My regression equation is from the article An OPS Question.

But this issue comes from a Paul Lebowitz article called Why the stat zombies ignore the Marlins. (Hat Tip: Baseball Think Factory) Here is the relevant paragraph:

"Most of the stat zombies predicted them as winning between 66 and 74 games. But it doesn't matter whether they win 80, 85 or 90 games; whether or not they make the playoffs or fade out at the end. They've built an organization that should be admired in the way that Michael Lewis's creative non-fiction Moneyball canonized the Billy Beane A's. Lewis tried to create an "age of enlightenment" in baseball inserting the Ivy League-educated genius into the game at the expense of those who can look at an athlete and find his talent regardless of what his stat sheet says. The numbers don't fit into that kind of analysis, so it's best to ignore it and hope it goes away; but it's not going away."

So some stat zombies did not correctly predict the Marlin win total. Mr. Lebowitz does not say who they were or provide any links. Also, I don't know if any stat zombies claim they have perfect foresight. There will always be things no one can predict. For example, who could have predicted that both Jim Rice and Fred Lynn would have had such outstanding rookie seasons in 1975 to propel the Red Sox to the AL East title?

But as I hinted at earlier, stat zombies were not the only ones to "ignore" the Marlins. The following links show they were not highly regarded before the season by non-zombies:

Chris Bahr's Predictions at the Sporting News (he predicted they would be 4th)

Sporting News Power Poll (the Marlins at #20 in mlb, 11th in the NL)

CNN/SI MLB 2009 Preseason Predictions

The last one had 13 experts and none predicted the Marlins to win the division or be the wild card.

One last thing. One stat zombie, Tom Tippett, of Diamond Mind baseball fame, has done a pretty good job of making predictions. You can read about that at 2005 Predictions -- Keeping Score. Look for the 7 year composite rankings towards the end. He did a very good job of predicting standings using his simulations from the Diamond Mind game. He was a also such a good stat zombie that he got hired by the Red Sox.

2 comments:

Joe said...

Well, I picked the Marlins to win 81 games, so I am pretty content with that. :)


http://www.statisticianmagician.com/

Cyril Morong said...

Joe

Thanks for dropping by and commenting. 81 sounds like a reasonable prediction.

Cy