Clay Buchholz has added a splitter this year to go with his well-known (and devastating) changeup. We first noticed this back when he was throwing one or two per game, but now it’s not unusual to see him throw a nice cluster of splitters in each start. A comparison between his pre-splitter and post-splitter pitch graphs is shown below:
Pre-splitter
Post-splitter
We’re now 66 pitches into the Clay Buchholz splitter experiment. How is it working out?
The most sensible thing to compare it to is the changeup, his other off-speed pitch. The two are virtually equally effective at generating groundballs (51.4 percent GB/BIP for the change, 50.0 percent for the split) or giving up line drives (16.2 percent change, 16.7 percent split).
The two major differences: swings, and swings and misses (whiffs).
Hitters swing at the splitter 63.6 percent of the time, compared to only 49.4 percent of the time for the change.
But hitters whiff at the splitter only 26.2 percent of the time, compared to 38.2 percent of the time for the change. In two-strike counts, hitters whiff at the change 30.4 percent of the time, nearly twice the rate at which they whiff at the splitter (16.7 percent).
Of the 66 splitters Buchholz has thrown, 44 of them have been to left-handed hitters, who’ve whiffed at 32.1 percent. Twenty-two of them have been to right-handed hitters, who’ve whiffed at 14.3 percent. Of course, for that last number, we’re talking only two whiffs out of 14 swings, so small-sample-size caveats apply.
Bottom line: if we had to evaluate the Clay Buchholz splitter experiment after only 66 pitches, it’s hard to say that the new pitch has been much more effective than his changeup. But in order to know for sure, more incisive analysis has to be done on his pre-split vs. post-split performance with other pitches.
Pitch Tags pulled from the PITCH INFO database. All information in this post can be viewed on Clay Buchholz’s player card on BrooksBaseball.net.
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To answer your question - no, it is not similar enough that he would have made the mistake. He was almost certainly commenting on the other developing pitch.
But none of these guys had a velocity separation between the two pitches of more than about 1 MPH, which is to say, negligible.
Buchholz is throwing an unusually slow change with (even more unusually) even less armside run than his 4-seamer, and a somewhat hard splitter with good, typical run in. There's no velocity overlap at all between the pitches. I haven't gone back to see if anyone else has done this in the pitch/fx era, but I think it's fair to say that, for hitters, it's something many or most have never had to deal with.
The pitches ought to be easy to confuse, so the key question may be whether the splitter is making the change even more effective.