53% of ABS
challenges have
overturned the ump.
The ABS Challenge System lets players dispute ball-strike calls via Hawk-Eye cameras. We track every challenge — who wins them, and whether it matters.
Season at a Glance
Through May 16, 2026The Headline Chart: Net Run Value vs. Win %
Each dot is a team. The x-axis shows how much run value they've extracted from ABS challenges; the y-axis shows their win percentage. Are the two related?
View as table
| Team | Net Run Value | Win % |
|---|---|---|
| STL | 5.44 | 0.591 |
| CIN | 5.40 | 0.533 |
| CHC | 5.39 | 0.644 |
| DET | 5.29 | 0.435 |
| KC | 4.76 | 0.422 |
| BAL | 4.65 | 0.444 |
| ATH | 4.19 | 0.523 |
| TEX | 4.13 | 0.477 |
| AZ | 3.57 | 0.488 |
| BOS | 3.49 | 0.409 |
| NYY | 3.27 | 0.622 |
| LAD | 2.91 | 0.600 |
| SEA | 2.81 | 0.478 |
| HOU | 2.77 | 0.391 |
| MIN | 2.71 | 0.444 |
| PHI | 2.42 | 0.489 |
| TOR | 2.23 | 0.444 |
| SD | 2.20 | 0.591 |
| SF | 1.98 | 0.400 |
| MIL | 1.91 | 0.595 |
| ATL | 1.86 | 0.689 |
| NYM | 1.41 | 0.409 |
| MIA | 1.20 | 0.444 |
| LAA | 1.07 | 0.356 |
| COL | 1.02 | 0.378 |
| WSH | 0.71 | 0.489 |
| CWS | -0.35 | 0.500 |
| TB | -0.50 | 0.674 |
| PIT | -0.51 | 0.533 |
| CLE | -0.52 | 0.522 |
Pearson r = 0.009. The correlation is weak. So far, challenge performance does not strongly predict winning. This could change as the sample grows. Methodology
Top Teams by Net Run Value
All 30 teams →| # | Team | Net RV Net run value above expected from ABS challenges. | Success% | Win% |
|---|---|---|---|---|
| 1 | St. Louis Cardinals NL | +5.44 | 58.4% | .591 |
| 2 | Cincinnati Reds NL | +5.40 | 60.0% | .533 |
| 3 | Chicago Cubs NL | +5.39 | 58.4% | .644 |
| 4 | Detroit Tigers AL | +5.29 | 61.0% | .435 |
| 5 | Kansas City Royals AL | +4.76 | 60.4% | .422 |
Top Players
Catchers by Overturn Rate
All catchers →Min 20 challenges
| # | Name | Rate | Chall |
|---|---|---|---|
| 1 | Carson Kelly CHC | 86.4% | 22 |
| 2 | Victor Caratini MIN | 78.3% | 23 |
| 3 | Dillon Dingler DET | 77.8% | 27 |
| 4 | Will Smith LAD | 75.7% | 37 |
| 5 | Salvador Perez KC | 75.0% | 32 |
Batters by Overturn Rate
All batters →Min 10 challenges
| # | Name | Rate | Chall |
|---|---|---|---|
| 1 | Maikel Garcia KC | 72.7% | 11 |
| 2 | Jose Altuve HOU | 69.2% | 13 |
| 3 | Sal Stewart CIN | 66.7% | 12 |
| 4 | Kyle Schwarber PHI | 63.6% | 11 |
| 5 | Ivan Herrera STL | 60.0% | 10 |
How to Read This Site
Net Run Value (Net RV)
The headline metric. It measures how much run value a team gains from ABS challenges
compared to what's expected. Positive = extracting value. This comes directly from
Baseball Savant's net_net_runs field.
Success Rate
Overturns divided by total challenges. Watch the sample size — a team with 3/5 is not meaningfully better than 40/80. We flag small samples throughout.
Correlation ≠ Causation
If challenge performance correlates with winning, that doesn't mean challenges cause wins. Better teams may simply be better at everything, including challenging. We're honest about this.
About Challenge The Ump
MLB's 2026 ABS Challenge System is the biggest rule change in a generation. No public site was aggregating this data in a clean format and connecting it to standings. So we built one — Challenge The Ump. Fully static, fully open source, refreshed daily from Baseball Savant. No tracking, no ads. Learn more →