The ABS System Has Created an Even More Extreme Velocity-Over-Everything Game

[Matthew Trueblood]

Image courtesy of Troy Taormina-Imagn Images

As is true whenever they make a change at your workplace, in baseball, everyone believes new things disproportionately disfavor them. Change is not welcome, and the more competitive the environment in which change is happening, the more suspicious everyone is of that change. I talked to many players about ABS this year, and while most of them acknowledged that the arrival of that system has made the game more efficient, few of them actually like it. Catchers miss the ability to politick for calls. Batters believe the system favors pitchers. Pitchers believe the system favors batters.

In general, it's pitchers whose complaints you should instinctively distrust. They're whiners, and they're paranoid. They constantly believe the league is out to get them, to help hitters and goose scoring. The old joke carries a kernel of truth, though: Just because you're paranoid, that doesn't mean they're not after you. This time, the pitchers are right, although it's true in an interesting way.

As I wrote at Baseball Prospectus in May, some teams immediately began asking their hitters to withhold their challenges and allow their catchers to use them, instead. Initially, it seemed to me that that was a simple response to the fact that catchers are better at challenging than batters are. That much is true, and it's important. Why not give the privilege of making ABS appeals to the guys who are more likely to win them, preserving your challenges and your right to challenge late in games, regardless of which side needs to do so in the big moments?

Since I wrote that, more teams have trended in the same direction. Catchers, in particular, had freer rein early in games, whereas batters seemed to get the green light only if and when their clubs still had challenges left in the late innings.

This is why, for instance, Jake Bauers told me in May that he felt like "pitchers have an extra umpire back there," and that batters get no value from the new system. The Brewers were one of the first teams to crack down on batter challenges; Bauers felt helpless. The zone could only get bigger, after the fact, for him.

In reality, though, something else was happening—something that hitters might have refused to acknowledge, but which pitchers could certainly feel. The zone has shrunk. Some of this happened last year, when the league changed the way it provided feedback to umpires on their zones in preparation for the implementation of ABS. It's gone further this season, as the ABS zone has come fully into effect. Umpires are now used to calling the zone that way, and when either side challenges, that's the zone that the computers enforce. It's a zone that stops about a baseball's diameter lower than it did in the past. 

What does a smaller strike zone mean? Firstly, it rewards patient hitters more. Secondly, it means they can groove their swings incrementally more, without paying as high a price as they would have in the past. If the pitcher has to aim for a smaller zone, the barrel can fill up more of it. Not by coincidence, the league's in-zone contact rate ticked up this year, to 86.1%. The league has trended toward more lifted, pulled contact for over a decade, and that trend didn't abate.

Surely, the league foresaw (and welcomed) the reduction in the size of the zone, on the premise that it would balance out some long-running trends favoring pitchers by increasing walks and/or forcing hurlers to throw more strikes. What they (seemingly) failed to anticipate, however, is that shrinking the zone would kill the remaining pitchers who were finding ways to win without plus raw stuff.

In some former version of the league, if you'd told pitchers that the zone was getting smaller and they had to start finding it, they might have been able to adjust. They would have been punished for not throwing as hard or having stuff quite as nasty, but they could have made up for it by pacing themselves differently, hunting early outs against weak hitters, and humping up against the stronger ones. They could have accrued value by piling up pitches and innings, even if they allowed a few more runs than they did before the change to the zone. But that's not the league we have now. In the modern game, pitchers can't pace themselves and ease off the gas against certain hitters, because even No. 9 hitters can take you deep. Besides, what counts as 'pacing yourself' or 'easing up' nowadays is just what they called maximum effort a generation ago. To beat these bigger, stronger hitters and all the fly balls they hit to their pull fields, you have to miss bats, so everyone has trained themselves to work right up to their bodies' red lines. There's no finding value by substituting dominance for durability; even the durable guys get hurt.

Instead, here's what happened: Stuff began to matter even more. Raw stuff—velocity, wicked movement, spin—was a markedly more reliable determinant of a starting pitcher's success in 2026 than in 2025.

Correlation Factors, Qualifying Pitchers, 2025-26

R-Squared	Stuff+		Fastball Velo.
Metric	2025	2026	2025	2026
ERA	0.29	0.31	0.12	0.15
xERA	0.53	0.59	0.17	0.40
FIP	0.49	0.54	0.18	0.44
xFIP	0.54	0.60	0.26	0.44

Shrink the zone, and batters can't be manipulated as well by the craftsmen of the mound. You need stuff you can beat hitters with even when you make a mistake in the middle of the zone. If you don't have that, you're in big trouble—not just bigger than a decade ago, but bigger than a year ago.

As you watch teams scramble to get to the fifth inning with many starters this postseason and turn to bullpen games to cover other innings, keep this in mind. Yes, part of the reason why we see more situations like those is that the playoffs have steadily expanded. That puts a higher percentage of the league's teams into the tournament, which means you no longer need a robust rotation to get there. It even means starting the games just one day after the regular season ends; that was not the way the transition from September to October worked even 15 years ago. Teams with weaker pitching staffs are being afforded less chance to rest and reset them before playing for their lives.

But there's also another factor driving the shift toward more relievers and shorter outings by anyone who can't throw 97. The rules changes celebrated by so many fans have had an unintended consequence: they make many pitchers who used to be downright good fringy, and some guys who were previously usable have become useless. That's going to disproportionately affect starters, but it also disproportionately hurts any team that doesn't have a wealth of young, live arms on hand. Maybe some reform of the new system will address this in the years to come, but for now, ABS has turned junkballers and control artists into piñatas. For a while, there was an understandable but not-quite-accurate idea that the league belonged solely to guys who could throw pitches that would snatch Babe Ruth's soul and leave nothing but toenails and urine in his shoes. That sense has become more accurate this year, which might not be good for the game. Just don't expect the teams in the tournament to keep pretending things are the way they were before. They've noticed these trends, too. They're just responding to them.

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[bean5302]

I think this is just more of a sign that pitchers don't pitch as much as they throw. There are some indications that pitching is under-rated. Bailey Ober, for example. He's been fairly effective with an 88mph fastball. Ober's never had great stuff. The fact his mediocre stuff has been effective with an 88mph fastball located pretty well says a lot about just being able to pitch.

Maybe some day, front offices will put down the iPad and look at results again.

[tucana25]

8 hours ago, bean5302 said:

I think this is just more of a sign that pitchers don't pitch as much as they throw. There are some indications that pitching is under-rated. Bailey Ober, for example. He's been fairly effective with an 88mph fastball. Ober's never had great stuff. The fact his mediocre stuff has been effective with an 88mph fastball located pretty well says a lot about just being able to pitch.

Maybe some day, front offices will put down the iPad and look at results again.

Totally agree. 

Breaking news: pitchers that can't hit their spots are actually less successful, new study finds. Batters hate it when pitchers learn this one simple trick.