10 Worst Umpires in Major League Baseball

9. Dan Iassogna
Iassogna is a fixture on these lists and is regularly referred to as one of the worst umpires in baseball. In 2023, he lived down to that reputation. Somehow, the 54-year-old Iassogna was promoted to crew chief in 2020, worked the 2023 League Championship Series. and has worked three World Series.
Umpire Dan Iassogna missed 14 calls in #NLCS game 3 #Diamondbacks v #Phillies.
— Umpire Auditor (@UmpireAuditor) October 20, 2023
He had a correct call rate of 89.4%. For context, last place Angel Hernandez had a correct call rate of 90.4%. https://t.co/QitKst2XEU pic.twitter.com/UbCQSb5e8y
In 30 games behind the plate Iassogna's accuracy was 93.4, which ranked 12th-worst. His CCAx of -21.5 was seventh-worst, he was fifth-worst in average consistency (92.4) and his AAx of -0.45, was eighth-worst. Kulpa also had some absolutely insanely bad performances. He had 18 games where he missed at least 10 calls. That gets you on this list.