Opening Day Umpire Preview: The First Day of the ABS Era
The ABS challenge system is live. We have five years of data on every umpire behind the plate. Here's what to expect on Opening Day and all season long.
5 min read
umpiresabspreview
Blog
Analysis, methodology, and original baseball writing.
The ABS Challenge System: What It Means for Umpire Accountability
MLB's Automated Ball-Strike System went live in 2026. Here's how it works, why our methodology already aligns with it, and what five years of pre-ABS data reveals about which umpires need it most.
8 min read
absumpiresmethodology
The 2025 Yankees Got +16.2 Runs of Free Umpire Favor. Here's the Full Story.
New York ranked third in ump run favor — but their WPA favor was negative. The calls went their way, just not when it mattered. Two pitchers explain almost everything.
6 min read
teamsumpiresyankees
Game 5 Was Perfect: The 2024 World Series Through Every Pitch
WPA charts, umpire scorecards, exit velocity overlays, and video highlights — the 2024 World Series clincher is the best demonstration of what a modern box score can be.
6 min read
productworld-serieswpa
Left-Handed Batters Get a Different Strike Zone. Here's the Proof.
Across five seasons and millions of pitches, the data is unambiguous: umpires call a wider outside corner for left-handed batters. ABS should fix it.
7 min read
umpiresanalysisabs
Your Team's Umpire Luck, Ranked: All 30 Teams in 2025
Toronto got +47.3 runs of ump favor. Baltimore got -20.7. Every team ranked, with run favor, WPA favor, and year-over-year trends.
8 min read
teamsumpiresrankings
Home Cooking Is Real (Sort Of): 12,449 Games of Evidence
Do umpires favor the home team? We tested it with five years of pitch-level data. The answer is more nuanced than the accusation.
9 min read
umpiresanalysisteams
Squeezed: The Pitchers Who Lost the Most to Bad Calls in 2025
Logan Webb got 165 free strikes. Mason Barnett lost runs to phantom balls. The full pitcher squeeze and gift leaderboard, with the data behind every ranking.
7 min read
pitchersumpiresrankings
The Most Consequential Missed Call in Every Season, 2021-2025
Five seasons. Five game-changing blown calls. Every one was a ball called strike on a 3-2 count. Every one would have been overturned by ABS.
9 min read
umpiresanalysisworst-calls
Angel Hernandez's Final Games Were Exactly What You Think They Were
78 games. 1,085 missed calls. A balls-called-strikes ratio of 8.3-to-1. Four seasons of Statcast-verified data confirm what fans always suspected.
8 min read
umpiresanalysislaunch
The Five-Year Verdict: Which Umpires Got Better, Which Got Worse, and Who Should Be Worried
Before ABS, we had five years of Statcast umpire data. Here's who was consistently elite, who was consistently below their peers, and what the pitch clock actually changed.
8 min read
umpiresanalysislaunch
We Built Our Own Umpire Scorecards From Scratch. Here's How They Work.
Every pitch tracked. Every missed call quantified in win probability. Here's how we built an umpire analysis engine from raw Statcast data — and why we measure impact differently than anyone else.
12 min read
methodologyumpireslaunch