MLB adds 10 new umpires as the position faces more changes than ever before (2024)

A flood of new umpires will patrol games this season with 10 rookies replacing retiring veterans across Major League Baseball, MLB vice president Michael Hill said last month. It will be the big leagues’ largest first-year class of umps in more than 20 years.

The newbies, ranging in age from 31 to 40, are joining a league that is rapidly evolving its rules amid a particularly anxious future for umpires.

This season, MLB will for the first time introduce a pitch clock, shift limits and larger bases, the league’s most seismic set of rule changes in nearly 50 years. And, for the first time this season, every Triple-A ballpark will employ an automated strike zone, so-called robo umps, after debuting the system last year.

MLB typically rotates a cast of 19 umpire crews in a season, each including four umpires who work the entirety of a series before moving along to another city. Those crews will see a thorough shakeup.

Tom Hallion was the longest-tenured among those umps who are retiring, with 30 years of experience. And Ted Barrett, who worked 26 seasons in the majors, is the only ump in baseball’s history to have worked two perfect games. Barrett was on the field when the Yankees’ David Cone pitched a perfecto against the Expos in New York in 1999 and when the Giants’ Matt Cain threw one against the Astros in 2012.

The other umps who are retiring: Jerry Meals (26 years of experience), Marty Foster (24 years), Greg Gibson (24 years), Jim Reynolds (23 years), Tim Timmons (23 years), Bill Welke (23 years), Sam Holbrook (22 years) and Paul Nauert (22 years).

Those umps are leaving behind a total of 243 years of collective experience. Together, they worked 16 World Series.

The last time baseball saw an exodus of umps to this degree came in 1999. That summer, the umpires’ union grew upset in their contract negotiations with the league and, unable to legally strike, instead resigned en masse, with 57 of them signing letters of resignation. By the next season, 22 of those umps had to be replaced. Eventually, 11 of those 22 were brought back.

Reynolds, as one example among those retiring, was one of those umpires hired to replace the lost 22 in 1999.

The new wave of umps includes 40-year-old Nick Mahrley, who worked the minor leagues since 2007 and has been a regular call-up ump, and 31-year-old Brennan Miller, who is now the youngest umpire on MLB’s roster. He is also the youngest rookie ump since Lance Barrett, who was 29 when he was promoted in 2014.

Beyond the knowledge drain that will follow those retiring umpires out the door, what level of accuracy is baseball losing?

Two sources for publicly-available umpire statistics, among several, offer us at least a glance at an umpire’s tendencies over time: Umpire Scorecards and Swish Analytics. And we can see where some of the retiring umpires and rookies fall on the scale of accuracy.

Umpire Scorecards culls data from the Hawkeye tracking system to determine if, when a batter takes a pitch, it was called correctly, using an algorithm to plot the likelihood the pitch was a strike. Their methodology is here. In these cases, we cross-referenced the results using Swish Analytics as quality control. And, for the most part, the results are similar.

According to Umpire Scorecard stats, here were the most and least spot-on umpires from behind home plate last season, by accuracy (ACC) and expected accuracy (AAX). The umpires in green are rookies; the umps in red are retiring:

The group of the most accurate umpires should not be a surprise. Three of them — Lance Barksdale, Pat Hoberg and Tripp Gibson — were part of the crew that umpired the World Series last season. Jeremie Rehak has been among the most accurate umps behind the plate in recent seasons. Adam Hamari has been umping since he was 12. And Alex Tosi, a rookie next season, was promoted for a reason, apparently.

Cross-referencing all these stats against Swish Analytics’ K-boost, BB-boost and run-boost stats — which measure each umpire’s calls relative to league average — surfaces most of the same names at the top and bottom.

The bottom of the list sees some familiar names, too. Greg Gibson and Marty Foster are among the 10 retiring umpires. CB Bucknor last season ticked off two managers in one half-inning in Arizona.

We should remember that the home plate box on television broadcasts is not an accurate view of the strike zone and an umpire has a better look at pitches. And we weren’t able to know what Bucknor, for instance, saw in those at-bats. But we also understand that a hitter of Nolan Arenado’s caliber has a good sense of where the zone sits, too.

And, it’s perhaps an endorsem*nt of today’s umpires that the most and least accurate of the bunch are separated by less than four percent of calls. It supports the idea that, overall, MLB umps are consistent — perhaps more than at any time in the measurable past.

“When you sign up to be an umpire, you’re not signing up to make new friends,” retired MLB umpire Dale Scott told The Athletic in 2021. “When people are yelling at me on the field, they don’t know Dale Scott. They’re yelling at a uniform. They’re yelling at the guy who made an out call they don’t like …

“But when you get into social media, with your name and your stats, it feels like a much more personalized thing,” Scott said. “They still don’t know Dale Scott. They read about him every fourth day after a plate job, or they see him on a goofy call on the bases, and suddenly it seems much more personalized, like they’re attacking you and not necessarily just a uniform that made a call.”

For a scale that intends to measure an umpire in a more holistic way, Umpire Scorecards offers average total run impact, which tries to add up the true impact of those missed calls. Here are those numbers:

More familiar names. Rehak debuted in the majors only in 2018 and was brought on full-time quickly afterward, in 2020. The World Series was apparently in good hands with Hoberg. The others are well-known among fans who keep scorecards at games.

Tom Hallion was crew chief for the 2021 World Series between the Braves and Astros and is retiring after a three-decade career of distinction. His Strike 3 call was perhaps the most recognizable in the league. Even casual fans can remember Hallion’s coincidental star turn, from a May night in Queens in 2016 when he had to talk Mets manager Terry Collins back to the dugout while defending the role of umps around the world.

The world wasn’t meant to hear that heated exchange. But it was a good reminder that an umpire’s job isn’t strictly to judge calls and enforce rules. They act as caretakers for the game, too. Their relationships and daily dealings with the people who play the game are just as important. And that can’t be measured.

In an interview with his hometown newspaper in Kentucky, Greg Gibson said of his retirement that he did not want to “be that guy where players are rolling their eyes when they see you coming out. I’ve seen that happen. I was getting to the point where it wasn’t fun.

“When I got into umpiring, it was my passion,” Gibson said. “I always said I wanted to leave when they still thought I was good. Not great, but good.”

(Photo of Pat Hoberg and Kyle Schwarber: Jerome Miron / USA Today)