Image credit: © Rhona Wise-USA Today Sports
Translated by Jose M. Hernandez Lagunes
The revolution will be televised. The MLB almost always does this, even if you have to look up which of the numerous networks and streaming services broadcast a given game. However, it is not a great revolution.
The first half of this two-part series delving into splitters found that, of the countless pitchers who played with a new splitter in the spring, only ten of them brought it with them in the regular season. Only one of those splitter rookies—Bryce Miller—seems to benefit appreciably from adding it to his arsenal. The other nine don’t throw it often or well.
However, off-speed pitches as a category are increasing in usage and effectiveness across the League, although it is more attributable to changes, as Robert Orr noted. Still, splitters have seen a modest increase in usage from 2.3% to 3.0%. The 10 guys who picked one is part of that, especially since the only guy who gave up his splitter this season is Joe Ryan, but it has more to do with pitchers already throwing one increasing their usage rates.
Thirty-six pitchers regularly threw a splitter in both 2023 and 2024, with the cutoff criteria set at 10 innings in both seasons and a minimum of 5% splitter usage in at least one of those seasons. Twenty-five are throwing it more often this year than last year, and 11 are throwing it less, but 22 are within five percentage points of their use in 2023 in either direction. Together, they average a three percentage point increase in the use of splitters. It’s not much, but it’s something.
The bigger question is whether or not throwing more splitters affects your performance. Surprisingly, those 36 pre-existing splitter pitchers are doing much worse than last year on average. Thirteen of them are within four points—above or below—of their 2023 DRA, well within one standard deviation. Four do it at least four points better than last season, but 19 do it more than four points worse. Here’s an especially sparse scatter chart.
Pitchers want to be below zero on the Y-axis because lower DRAs are better, but most are near or above the line. For many of them, this has to do with more important factors than the use of the splitter. That spot at the top is AJ Puk. The poor guy had a DRA- of 74 in 2023, but he exploded to 145 this season before the Marlins put him on the disabled list with shoulder fatigue. That may or may not be code for, “This guy sucks right now and we need to take him off the active roster while we figure out how to fix him.” He increased his splitter usage from 1.5% to 9.0%, but the pitches he throws the other 91% of the time are the main culprit for his bloated DRA. The splitter is the least of his problems.
As can be deduced from the graph, there is no relationship between the change in hitter usage and the improvement in DRA-. The correlation between them is -0.01, which is impressively close to zero. There is probably the strongest correlation in the world between people who don’t like broccoli and people named Steve. Many of them are simply not doing anything different. It doesn’t make sense that Ryne Stanek’s splitter usage has dropped from 18.1% to 17.6% and that his DRA- has improved from 108 to 107. He’s the same pitcher, but with the same DRA-. He’s the same pitcher, both ways, as last year.
However, there are some fascinating individual cases. No one has increased his splitter usage more than Jordan Hicks, who threw it 1.6% of the time in 2023 but is using it 22.1% in 2024. The fact that his DRA- has worsened 12 points, going from 75 to 87 , is irrelevant due to his role change. As a reliever with the Cardinals and Blue Jays, all he needed was his triple-digit sinker and a slider to keep him balanced. Now that he’s a starter for the Giants, he has to add a third pitch. His velocity is down four points, but he’s already more than halfway to reaching last year’s innings total in six starts, and an 87 DRA-starter is much more valuable than a 75 DRA-reliever. That 1.6% splitter usage last year was proof of concept that he could add a third pitch and make the conversion to the rotation.
The biggest decliner in splitter usage is also a Giants starter who added a third pitch. Last season, the only pitcher who threw it more than half the time was Keaton Winn, who had 55.1% usage of the splitter. Only three pitchers have used an off-speed pitch more: Tommy Kahnle (changeup? screwball?), Trevor Richards (changeup) and Devin Williams (airbender). This season, he has cut 12.1 points in his splitter usage to incorporate a breaking ball—his slider usage has risen from 3.5% to 13.6%—but his 42.0% splitter usage remains the highest in MLB among players. starting pitchers*.
Splitters can absolutely be a catalyst for improvement in individual cases. Cal Quantrill has the second-biggest increase in splitter usage—from 13.0% to 31.5%—and lowered his DRA—from 139 to 117. That means he’s simply a bad pitcher rather than a candidate for a roster stint. injured due to phantom injury, which qualifies as a great success on the Rockies scale.
On average, the 36 pitchers have improved slightly at throwing splitters this year according to PitchPro y StuffPro, going from -0.6 to -0.7 in the first and from -0.7 to -0.8 in the second. George Kirby is one of the best in the game, rated -2.0 PitchPro y -1.4 StuffPro. Here he is in action against Will Benson:
Despite his evil, he only uses it 9.8% of the time. Maybe it’s because his other five pitches have a -0.4 PitchPro rating or higher, or maybe it’s because he’s had a few of these:
That was a vicious splitter and got a swinging third strike, but the batter reached base anyway when it bounced away from the catcher. He has three wild pitches in 32 and ⅓ innings this year after just five through the first two years of his career, which spanned 320 and ⅔ innings. Catching a splitter is difficult, but it’s worth the risk of throwing it if it’s as good as Kirby’s.
Splitters are on the rise—though more like the gentle flow of an incoming tide than the tsunami it seemed to be in spring training—but there’s nothing common or universal about their use or effectiveness among pitchers who throw them. Each launcher with a splitter is an individual case study. Splitters are fashionable, but they are not a revolution.
*Winn’s usage data does not include Sunday’s outing, in which he pitched 31 splitters on 80 pitches, or 39%.
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2024-04-30 13:18:17
#splitter #revolutionpart
