Optimal ABS use and how the Royals have handled challenges

KANSAS CITY, MO - MARCH 30: Maikel Garcia #11 of the Kansas City Royals signals for an ABS challenge against home plate umpire Alex Tosi in the fifth inning during the game between the Minnesota Twins and the Kansas City Royals at Kauffman Stadium on Monday, March 30, 2026 in Kansas City, Missouri. (Photo by Mikayla Schlosser/MLB Photos via Getty Images) | MLB Photos via Getty Images Adding the ABS challenge system generated a lot of buzz early on for MLB, and I think it is a good addition for the most part. Teams have been taking different approaches when it comes to challenging, so looking at the data a few weeks in to see what the Royals are doing relative to their peers seemed like something that might be instructive.

Going into this, I had some general, broad ideas of what teams should do with respect to challenging. You want to challenge fairly often, meaning your team should almost never have a game with zero challenges unless it is a 12-1 blowout. This will almost certainly lead to new unwritten rules about challenging when ahead by too much.

There is no downside to challenging in a lot of situations, especially while you still have two challenges remaining. But there is a balance, Travis Sawchik had a good piece at MLB. com about using ABS in different counts and leverage situations .

Talking about leverage and count complicates things though, and you don’t want your hitters spending mental effort at the plate thinking about the value of challenging in a given situation. So, you want the team’s process to be relatively simple, moderately aggressive, and not put too much value on losing a challenge so that players become reticent to pull the trigger. So far, 54% of challenges have overturned the original call according to Baseball Savant.