If Aroldis Chapman’s splitter is here to stay, he could be better than ever

Through his first three games of the young 2021 season, Aroldis Chapman has been nothing short of dominant. He recorded his first save of the season last night, and looked sharp in his non-save situation appearances as well.

Before addressing Aroldis’s crucial new addition to his arsenal, it’s worth noting that he seems to have regained access to the very best versions of his offerings from previous seasons. Already, Chapman’s delivered a 102 mph pitch for the first time since 2019, and his average fastball velocity is currently 99.2 mph, 1.4 mph faster than in it was across his 2020 campaign. The early returns seem to suggest that a full spring training and a normal schedule have set Chapman on the path towards a more dominant season than his previous one.

As early as 2013, Chapman experimented with the addition of a splitter to his already dominant fastball-slider combo, but never threw one in a regular season game until he K’d a trio of Blue Jays on them across back-to-back outings last September. That week, Peter optimistically addressed the potential for the pitch to develop into a dangerous weapon.

With four swings and misses on four splitters, the pitch seemed to be — at the very least — a worthy alternative to the divergently breaking slider, especially against righties. A couple of months later, I was even more bullish about Chapman’s splitter’s viability against big league hitters on a relatively high usage.

In four inning-long appearances so far this season, much to Peter’s and my delight, Chapman’s thrown seven splitters, already three more than he had across the entirety of his career prior to this season. Of this season’s seven, all have been thrown on two-strike counts, leading to two taken balls, and five swinging strikeouts. Still, no batter has made any contact with this filthy split-fastball.

Taking a look at the way this thing falls off the table in comparison to his four-seamer, it’s not hard to see why:

Of course, as Peter and I pointed out in our previous pieces on the pitch, its current effectiveness is certainly heightened by the fact that batters aren’t ready for it. Since Chapman has now thrown the splitter about an eighth of the time this season, batters are sure to soon grow keen to Chapman’s willingness to utilize the pitch. Also, Chapman’s so far only thrown the pitch in two-strike counts, meaning that for now, batters can rule it out at the onset of at-bats against him. To access the full benefits of a third pitch, Chapman will need to begin throwing it in all counts in order to keep hitters constantly guessing, instead of just when they get into a hole.

Peter summed up the splitter’s effect on Chapman’s other pitches thusly:

We all know how fickle Chapman’s fastball command can be. Once a hitter is able to eliminate an offering from a two-pitch pitcher, his job becomes that much simpler — all he has to do is wait for Chapman to throw a hanger. Throw a third pitch into the mix, and all of a sudden, it’s back to a guessing game for the batter.

As Peter presciently noted, Jose Altuve ended the Yankees’ previous season by sitting on a slider when Chapman lost his feel for his fastball. In the Yankees’ most recent playoff run, again Chapman allowed an eliminating homer to Mike Brosseau in the ALDS’s decisive fifth game. This time, however, it was Chapman’s offspeed that gave him trouble, as Brosseau correctly predicted a 3-2 fastball on the tenth pitch of the at-bat when Chapman couldn’t find the zone with his slider, parking it into the left field bleachers. In that at-bat, Chapman actually even threw an 0-2 splitter, after striking Brosseau out on one the day before, but missed wildly with it up and away. Ideally, Chapman would be able to throw not one, not two, but all three pitches for strikes in any count, avoiding these kinds of scenarios that handcuff the efficacy of his sucio stuff.

Still, Chapman’s been more democratic with his pitch mix this season than ever before, throwing four-seam fastballs just over half of the time, by far the lowest rate of his career. In its stead, Chapman has made room for the splitter, and thrown his slider with the second-highest frequency of his career.

By edifying the quality of his preexisting duo of offerings, and adding in a third, genuinely elite pitch, Chapman has been even better than he was when he threw his hardest. So far, he hasn’t allowed a run, and has struck out 73.3% of the batters he’s faced, nearly double his perennially league-leading career average of 39.9%. While the strikeout number is unsustainable, the addition of a splitter should grease the wheels for some additional effectiveness of the other two pitches. If Chapman’s pitch mix continues to diversify, he now has the stuff to avoid previous pitfalls, cementing himself as the most dominant relief arm, in pinstripes or otherwise, since the final major leaguer to wear number 42.