A Couple 2,3 Thoughts On ABS Challenges

We’re only a week into the season, but the Automated Ball-Strike Challenge System the MLB introduced this year is already a topic of discussion. Views range from the pure joy of humiliating umpires to the dismay of taking away human judgment from the game. I land somewhere in the middle on this, but first let’s show the rules and how it works. This is directly from Baseball Savant:

A Fun Thought

I absolutely love that this system has caused teams to list the actual height of the player. Now, we already got that satisfaction on the Andrew Vaughn front in 2025, but seeing Gavin Lux shrink 3 inches was also fun (Connor Wong and Tucker Barnhart also lost 3 inches). It’s a silly thing overall, but just funny to recognize how they’ve been bullshittin’ for years.

A Strategic Thought

From the stats we’ve seen so far, it’s pretty obvious that teams have told their pitchers to not challenge and leave that to the catchers. This is an optimal strategy, and in practice, it’s clear teams are employing it as pitchers have challenged 12 pitches, while catchers have challenged 168.

On the hitting side, I think there had to have been instructions handed out, like only our best hitters get to challenge. However, there are some outliers. Tristan Peters challenged a pitch the other day, to which I turned to BeefLoaf and said “they should bench his ass for that”. Jose Caballero, who made the first challenge (and lost), is among the league leaders in challenges (3). Now, he does walk at a pretty good clip, but is that really the guy you want using challenges? He’s 2 for 3, but still. This is something I expect to change rapidly. Could you imagine Aaron Judge up in a big spot and can’t challenge because Caballero used ’em up? I have to imagine that by the end of April, the hitters with the most challenges will be the best hitters in the game.

A Fundamental Thought

This system strives to be too perfect. The ball crossing a plane in the middle of the plate at a specific percentage of the player’s measured height and the width of home plate sounds like a precise measurement. But is it? The league provided the following to The Athletic in regard to the accuracy:

This is a high level of confidence, but you and I have already seen calls made within that range. If you haven’t seen them, Baseball Savant has a chart of the calls that have occurred and there are overturned calls within that range:

The call above was .1″ within the strike zone, causing Caleb Durbin to strike out, but was the umpire really wrong? The batter’s stance is not taken into account and from what I can find spinal compression is not either, which sounds like a nit pick, but it was considered when measuring the players. Measuring them at 10am-12pm to get them at their tallest. When we’re talking .1″, that matters, just like an 8th inning strikeout matters.

This is no reason to throw the system out or even say it’s really problematic. I simply think there should be an interval that defers to the umpire’s judgment. This is the same way most replay systems work and it is widely accepted that some challenges end in inconclusive evidence. The league has already stated a 99% confidence in the location being within .48 inches of where ABS states. So make a 1 inch zone, half an inch inside, half an inch outside. If the ball lands there, the umpire’s decision stands. You know, except CB Bucknor because he prolly just guessed anyway.

I am not the first to propose this, in fact, the MLBPA polled players on this idea and it didn’t have enough support to push for it. But now, seeing it in practice for only a few days, I wonder if it will get some attention. I think it should.

Overall, I like the ABS system. It will help with games where we previously would have had to suffer through poor umpiring or even just boos from people sitting in my section behind the foul pole who could not have possibly determined a ball or strike. But before I go full Mayor of Drugachusetts and declare ABS awesome, I think the inconclusive zone needs to be implemented.

-Chorizy-E