As Eno pointed out last week over on the RotoGraphs side, Trevor Hoffman is struggling right now. He’s currently sporting a FIP of 10.50, XFIP of 6.62, and a WPA of -1.54. Is there anything in the data that sheds a little light on the problem? Perusing the data there are some things that stand out, notably pitch usage, contact stats, and an extreme fly ball tendency.
As Eno already noted, Hoffman is using his changeup much less this year than years past (21% compared to 29% career average) with his fastball picking up the some of difference (66% to 63% career average). In order to dig a little deeper I looked at Hoffman’s page in Texas Leaguers’ pitch F/X database and ran some splits by year on pitch utilization. The largest discrepancy was, not surprisingly, the changeup. The surprising part to me was that the drop from last year to this year was larger against RHB (32% in 2009 to 10% in 2010) than it was against LHB. This could be a key piece of information as most of the HR’s Hoffman has given up have been on fastballs to RHB. Could right handed batters just be ignoring the changeup and sitting on the fastball?
Also of interest is that Hoffman has struggled at getting swings and misses so far this season. Looking at Hoffman’s plate discipline stats, we see an abnormally high Contact% (88% compared to career 75% career). Also of particular interest are the results on pitches out of the zone. Hoffman is only getting swings on 20% of pitches out of the zone, and even when he does get swings he only gets swings and misses 22% (compared to 48% for his career) of the time. Turning back to Hoffman’s Texas Leaguers’ page, the culprit again appears to be his changeup, which has gone from getting whiffs 20% of the time in 2009 to only 9% of the time in 2010.
As I said in the intro, up until this point in the season Hoffman has become even more of a fly ball pitcher than normal. He currently leads all qualified relievers in FB% by a large margin with 71.8%, which is offset by an astonishingly low GB% of 12.8%. This is even more problematic when you sport a 21.4% HR/FB ratio as Hoffman currently does. Will the ratio remain that high? Probably not, but even if it comes down to a more respectable number it still will not solve all of his problems as his still high xFIP indicates.
I’ve thrown a bunch of various percents your way this morning, so I should probably summarize. Hoffman’s throwing his bread and butter pitch, his chanegeup, less than in years past. He’s getting fewer swings and misses, again notably on his changeup. He’s been giving up flyballs at a dizzying pace, which has also led to giving up HRs at a dizzying pace. So far this has all added up to disaster.