Lots of hitters perform better at home than on the road, but Kevin Youkilis’s career splits are pretty big:
For a rough comp, here was the 2011 home-road split for all of MLB:
So league-wide, hitting at home last year was good for .006 points of batting average, .011 points of OPB, .017 of slugging. Youkilis’s split was +.033/.023/.045. Or, if you like one number, Youkilis’ home-field OPS bump of +.069 is more than four times greater than the league’s. I went back and looked at the decade of league splits and it turns out that the home-field boost 2011 is on the small end, so assume the difference between Youk’s split and the league’s is closer to two-to-one than four-to-one, it still appears that we’re looking at a decent-to-good hitter turned into a very-good-to-outstanding one by Fenway Park.
By contrast, his slash at Chicago’s Cellular Field, his new home, is an anemic .234/.341/.390 for an OPS of .730 in 91 plate appearances. Do I expect that to improve? Sure. But I doubt Youkilis will ever be the hitter at U.S. Cellular that he was at Fenway.
At this point people will chime in with park-adjusted stats that show Youkilis is a very good hitter no matter how you slice it. Okay, fine. But I don’t love park-adjusted stats because they don’t take into account how hitters change their basic approach depending on where they are hitting. And I think this is especially true for hitters in Boston. Years ago I looked at splits, and more crucially the spray charts, for the ultimate great-at-Fenway-mediocre-everywhere-else hitter of his generation, Mike Lowell* and it was completely obvious he had a different strategy at the plate in Fenway — one involving peppering a kelly-hued wall of uncommon size with lame fly balls. Of course, I can’t find that work to repost here, so I’ll just have to wave my hands and tell you to do the research yourself if you don’t believe me.
*.856 career OPS at Fenway, .805 overall. But that doesn’t tell the whole story. In 2007, his best year in Boston, Lowell’s home/road OPS split was a gaping .993/.767.