Thursday, January 21, 2010
Center Field Defense: A Closer LookPosted by Sean Smith
Last year my TotalZone ratings gave Torii Hunter an excellent +12 rating. Due to an injury Torii only played 115 games in center, most of the other starts went to Gary Matthews Jr., who TotalZone absolutely hated out there for a -18 rating in only 435 innings. If both of their ratings were prorated to 162 games, Torii would be an unbelievable 80 runs better than Matthews. Let's look into some of the detail available through retrosheet:
Fly Balls: Of the flyballs hit to center field (fieldedby =8, either the CF catches the ball or eventually retrieves it and returns it to the infield) Hunter caught 85%. Matthews only caught 72%. Matthews gave up slightly more singles, but many more doubles (15.6% to Hunter's 6.5%). Matthews allowed a few more triples, though in either case we're talking about 1% of flyballs.
Line Drives: These are, as you might guess, much harder for an outfielder to catch. If it's not hit right at you or at least pretty close, you aren't going to catch many line drives. But of the ones hit to center against the Angels, Hunter converted a much higher percentage, 14% to only 6% for Matthews.
Totalzone cannot tell us if Matthews had much tougher chances than Hunter did. These numbers are so extreme that it is very likely Matthews faced a tougher set of flyballs and linedrives, and the difference in their skill level is not quite this extreme. I wondered about scorer bias. Maybe the stringers hate Matthews (like many Angel fans) and if he misses a borderline play it's called an easy fly ball, where if Torii missed the same chance it would be condidered a tough line drive. This is probably not the case, there were more line drives (31%) among Hunter's chances than among Matthews' (28%), but not enough to explain the results.
How do these ratings correspond to actual team runs? With Hunter in the field, the Angels gave up only 4.12 runs per 27 outs. With Matthews, they gave up 5.33. I wondered if the mix of pitchers could explain this. What if Hunter was playing behind Jered Weaver more often and Matthews was chasing lasers hit off Santana? I looked at the runs allowed by pitcher for every pitcher who had at least 15 innings in front of both, and 11 of 12 Angel pitchers prefer Hunter. Only Sean O'Sullivan pitched better with Matthews behind him. For John Lackey the difference was small (.06 R/G) but for Weaver (2.72 to 5.72) and Saunders (3.70 to 7.90) the difference was enormous.
I'm not telling you that Matthews really costs a run per game compared to Hunter, random effects are likely a big part of this observation, but I'm convinced that Matthews' days as an Angel should come to an end. They still owe him 23 million over the next 2 years, but the Angels will be better off with Reggie Willits, Chris Pettit, or Terry Evans backing up in the outfield. their chances of winning another AL west title would be even better if Matthews is released and signs with a division rival.
Sean Smith is a lifelong Angels fan despite never visiting the west coast until April 2006. His work can also be found at baseballprojection.com and Anaheim Angels All the Way and he can be contacted by email.