Do you aspire to be PECOTA?
Not Bill Pecota, the late 80s-early 90s Royals infielder who smacked 22 lifetime home runs.
PECOTA, Baseball Prospectus's "Player Empirical Comparison and Optimization Test Algorithm."
It's one of several super-heated statistical projection systems that help filter out some of the noise to determine how today's Major Leaguers might perform next year based on their past performance, age, injury history, and how similar ballers have performed at the same point in their careers.
As I mentioned last post, PECOTA and its cousins have a WAR of about two. They're contributing team players but you're not winning the pennant with them. They excel at pointing out the ravages of age on players. They can't predict big surprise performances.
In fact, you can be your own PECOTA if you keep these rules in mind:
1. Hitters tend to peak around 26-29 and thereafter decline.
2. Pitchers' peaks are more varied and can occur later.
3. Hitters' batting averages can fluctuate because of varied BABIP, but walk rates tend to remain fairly constant.
4. As they age, everyday players lose speed, walk and strike out more, steal fewer bases, play worse defense and hit more home runs.
5. Lumbering first basemen and DHs tend to lose their skills and their value quickly. Speedsters tend to age more gradually.
6. After about age 36, even the healthiest everyday players begin breaking down and losing time to injury.
7. Players who have one anomalous season after several years of significantly better or worse performance tend to regress to the mean the following year. That is, a third baseman with a .250 lifetime batting average and 15 homers a year who bats .300 and goes yard 35 times this season is likely to bat around .275 with 25 taters the following season.
8. Players who have anomalous first half seasons tend to play to their projection in the second half, not withstanding injuries and other externalities.
9. Players who enter the league late tend to leave it early. Think Evan Gattis.
10. Hitters who enjoy unusually high BABIP, and pitchers who allow unusually low BABIP, are generally hoodoos and fakes who will pay the piper the subsequent season. (The reverse is also true.) "Unusual" is relative to a player's own experience. Ichiro had ridiculously high BABIP every year because of the way he went about hitting.
11. Pitchers can seem to have great or poor ERAs because of the defense behind them. Examining "Fielding Independent Pitching" statistics offers a more accurate window into the future.
12. Pitcher ERAs rise when they move from the NL to the AL (and vice versa) mostly because of the DH.
13. Pitcher ERAs fall when they leave the rotation and enter the bullpen. It's easier to subdue batters for one inning than for seven. Moreover, relievers tend to face same-handed batters; starters tend to face lineups constructed to defeat them.
14. Baseball players are humans. They are unpredictable. That's what makes the game fun.
You are armed. Go out and predict the future. Be PECOTA.
(Next post, we'll examine some of the interesting projections. With a grain of salt, of course.)
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