Manny Ramirez and the Big Green Wall

How bad is Manny Ramirez on defense? If you look at UZR, or either my or Chris Dial's zone rating based systems, you get at least -30 runs last year. From John Dewan's defensive bible, he's at -14 plays, and -31 enhanced. From David Pinto's PMR at Baseballmusings.com, he's worse than -20.

Are these numbers right? Or do these play by play methods not properly adjust for that big green wall behind him?

I recently received a database with complete ZR information for all players back to 1987. I decided to look at matched innings for players who have played left field for the Red Sox and for other teams. Jim Rice and Mike Greenwell are not in this sample, having never played anywhere else. Neither is Ramirez, who played only RF in Cleveland. If a guy played 1100 innings in left field elsewhere, and 75 in Fenway, he gets his ZR runs prorated to 75 innings for the sample.

When all is said and done, I had about 6400 matched innings. The players, per 162 games, were -25 in Fenway and -10 on the road.

This sample isn't huge but I think its a fair enough estimate. I would be a lot more confident if I had home /road defensive splits, but those are not available.

So for this year, Manny is at -23 so far. Add back in those 15 runs, prorate by his inning played total, and Manny's new rating is -14.

This adjustment is greater than I thought it would be, I figured -7 last year when I had much less data. Manny is a bad outfielder, but nowhere near as bad as some metrics make him out to be.