Monday, March 07, 2005

Baseball Prospectus 2005

I just received my copy of Baseball Prospectus 2005, and have been enjoying it so far. Sure, the Win Expectancy article is written so poorly (not even counting the typos) that it is almost impossible to read, but the ideas are so interesting that it is worth the extra effort.

However, when I started to go through the player pages, the entry for Barry Bonds brought me up short:

Do steroids, all things considered, improve a baseball player's performance? For all the hand-wringing, moralizing, and high-horsing the issue has triggered, the net effect of steroids on baseball players remains unknown. ... As performance analysts, we're far more interested in the on-field effects than anything else. Given the obvious difficulties in setting up control groups of major league players using and not using, it's unlikely we'll find anything conclusive anytime soon.

... At the end of the day Bonds remains the best hitter in baseball. He posted the best on-base percentage of all-time and one of the highest slugging averages ever in '04, well after the first steroid rumblings were supposed to send baseball's sluggers back down to Earth. Bonds will remain the best hitter in the game in '05, though injuries and age will start cutting into his production. We'll leave the moral outrage to someone else.

Where to start with this? First, as "performance analysts", BP should start with the numbers, something they are always telling other people to do. Even a preliminary analysis (like the one I began here) shows that Bonds' performance since age 34 (when he started associating with known steroids peddlers) goes dramatically up, even though EVERY OTHER comparable baseball great goes down (yes, even Hank Aaron). As Dexys put it, you don't need a degree in stats to know that such a result is multiple standard deviations away from "normal".

Moreover, the BP "analysts" should be VERY concerned as to whether Bonds took steroids -- because if he did, then his numbers show their effects, not his achievements relative to other ballplayers who were not taking them. Just as we've learned from them that RBI tells us more about a team around a player than the player himself (hello Vinny Castilla), we should know when the numbers tells us more about the advantage a player has given himself over other players through steroids. And frankly, figuring out a way to isolate the effect of steroids in stats is more important than new fielding stats right now.

Finally, what bugs me most about this is the last line. By saying that they will leave the "moral outrage" to others, they ARE taking a moral stance: that those who question Bonds and his stats are not asking legitmate questions. It also strikes me that they are upset that reality has entered their world of getting excited about Bonds' player card every year, and they are simply in denial about objective proof against their worldview. Actually, it's funny -- they sound like a bunch of scouts complaining about "Moneyball".


At 5:43 PM, Anonymous Anonymous said...

There is one other factor to consider and that might be park factors. I don't know exactly when SBC opened (2000?), but isn't it a better ballpark to hit it than Candlestick was? I'm not trying to say that steriods aren't evil just that there may be multiple factors skewing the data that you show (including harder balls and bats).


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