Trevor Hoffman returned to action on Sunday, but not as the closer of the Milwaukee Brewers. Hoffman instead returned as the setup man, recording a perfect inning including a strikeout. He threw 9 of his 10 pitches for strikes. Everything appeared to be as it was during last year’s excellent run. Has anything actually changed, though? Hoffman recorded a perfect inning on May 16th against the Phillies and then proceeded to blow a two run lead against the Reds on the 18th. That would be his last appearance before being shut down by Ken Macha and Rick Peterson.
The first question, to me, is what to even look for. Hoffman’s velocity was slightly down, but the main problem appeared to be a lack of command with both the fastball and changeup. Peterson and Macha determined that it was a mechanical problem.
Macha and pitching coach Rick Peterson discussed the arrangement in a brief chat with Hoffman on Friday. On Saturday, Hoffman took part in his second pregame bullpen session with Peterson, working on mechanical adjustments related to arm slot that Peterson believes will add more downward movement to his pitches (emphasis mine).
In that case, if the hiatus and mechanical tweaking that Hoffman and Peterson worked on was successful, we should see a marked drop in vertical movement on Hoffman’s pitches. Entering this appearance, Hoffman’s fastball averaged 12.6 inches of vertical break as measured against a hypothetical spinless ball. The positive number indicates rise, a negative number would indicate drop. His changeup averaged 5.8 inches of vertical break. Both numbers are consistent with his results from last season. The positive numbers on these pitches are unsurprising – the fastball and changeup, due to the way they are gripped, typically exhibit rise.
On Sunday, Hoffman’s fastball exhibited only 10.3 inches of vertical break and his changeup only 3.6 inches of vertical break. It certainly appears, then that the mechanical tweak was successful. Of course, we’re dealing with a sample size of five fastballs and three changeups – very hard and tough to make a judgment on. Let’s take a look at things appearance-by-appearance over the month of May to see if Sunday’s appearance was anything we hadn’t already seen from Hoffman.
His fastball vertical movement actually was quite lower than it had been in any of his appearances throughout May. His changeup vertical movement was lower than most of his other appearances, except for his 5/16 appearance against PHI.
The idea of reducing vertical movement on Hoffman’s pitches likely has one end – more ground balls. Hoffman has always been a fly ball pitcher and has succeeded particularly when he can keep balls in the park. That just doesn’t appear to be happening this season. The easiest way to keep a ball in the park is to not let it leave the ground in the first place, and less vertical movement likely means more ground balls for Hoffman. We’ll have to wait and see more appearances to see if this reduced rise is real and if it will lead to more ground balls. At least we can say that early results are encouraging.