Sunday, January 21, 2007

PECOTA Unkind to Sheffield

The PECOTA forecasts are up at Baseball Prospectus. The PECOTAs are premium content requiring a paid subscription so I can't go into too much detail but I'll give you a little preview. First, PECOTA forecasts are based on comparisons with about 20,000 Major League players since World War II and about 15,000 minor league players since 1997. Each current player is compared against all the players in the database and projections are made based on the careers of similar players. They are matched on performance metrics such as bating average, isolated power, walk rate and strike out rate. Other player characteristics such as career length, fielding position, handedness, height and weight are also considered.

Looking at the Tiger batters, the biggest surprise to me is Gary Sheffield who has a PECOTA weighted average projection of .279/.351/.436. PECOTA is one of the best projection systems and I generally think most of the forecasts are reasonable but this one seems too pessimistic. Sheffield is 38 years old and coming off a wrist injury so a decline is certainly possible but I think PECOTA is not taking into account that last year's sub-par stats (.298/.355/.450) were more injury related than age related. In 2005, Sheffield batted .291/.379/.512 and was batting .341/.390/.516 through April, 2006 before injuring his wrist. If the wrist is completely healthy as he claims, I see no reason why he can't come close to his 2005 numbers again.

Here are a few other notes on Tiger batters:
  • Curtis Granderson is expected to have an .800+ OPS and could do significantly better. He has a 20% break out rate which means he has a 20% chance to improve his stats by at least 20% next season. Granderson's closest comparison is Ray Lankford and I don't think many would complain if he had a career like that.
  • Chris Shelton is projected to have an OPS over .800 which would be significantly better than Sean Casey's sub-.750 OPS projection. Casey also has a 29% attrition rate which is the probability that he will see his playing time cut in half by injury or poor performance. Casey's closest comparison is Hal Morris who is actually the first player I would name if you asked me to compare Casey to a past player without looking up statistics.
  • Carlos Guillen has the best projection on the team as he is expected to reach an OPS of .870. This would not be as good as last year but still outstanding for a middle infielder. It's also nice to see that his attrition rate is only 3% although I'm not quite that confident in his health.
  • Marcus Thames is projected to have an OPS above .820 but his collapse rate (probability of 20% drop in performance) is 43%. His comparables are Kevin Mitchell and Jose Canseco. I certainly wouldn't mind him seeing him have a couple years like those guys did in their primes but I'm not expecing quite that kind of performance.
Next time, I'll look at a few pitchers.

No comments:

Post a Comment


Blog Archive


My Sabermetrics Book

My Sabermetrics Book
One of Baseball America's top ten books of 2010

Other Sabermetrics Books

Stat Counter