54% 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 September 22, 2026Net Run Value vs. Win %
Pearson r = -0.176 · Weak correlation
Each badge is a team. The x-axis shows how much run value they've extracted from ABS challenges; the y-axis shows their win percentage. Click a team to highlight it.
View as table
| Team | Net Run Value | Win % |
|---|---|---|
| CIN | 11.12 | 0.462 |
| ATH | 9.85 | 0.391 |
| CHC | 8.85 | 0.558 |
| DET | 7.71 | 0.471 |
| TEX | 6.19 | 0.500 |
| KC | 3.94 | 0.429 |
| AZ | 3.43 | 0.526 |
| NYY | 2.64 | 0.574 |
| ATL | 2.64 | 0.590 |
| LAD | 1.60 | 0.615 |
| PHI | 0.83 | 0.551 |
| SF | 0.60 | 0.414 |
| TOR | 0.46 | 0.490 |
| STL | -0.08 | 0.487 |
| BOS | -0.16 | 0.538 |
| COL | -0.36 | 0.365 |
| MIA | -0.38 | 0.487 |
| LAA | -0.55 | 0.385 |
| MIN | -0.97 | 0.465 |
| BAL | -1.61 | 0.484 |
| HOU | -3.16 | 0.494 |
| SEA | -3.37 | 0.468 |
| MIL | -3.76 | 0.628 |
| WSH | -4.28 | 0.465 |
| NYM | -5.06 | 0.455 |
| TB | -5.58 | 0.613 |
| CLE | -5.64 | 0.519 |
| SD | -5.89 | 0.558 |
| CWS | -11.23 | 0.513 |
| PIT | -11.59 | 0.506 |
Pearson r = -0.176. 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 | Success% | Win% |
|---|---|---|---|---|
| 1 | +11.12 | 61.5% | .462 | |
| 2 | +9.85 | 60.4% | .391 | |
| 3 | +8.85 | 59.0% | .558 | |
| 4 | +7.71 | 58.0% | .471 | |
| 5 | +6.19 | 58.2% | .500 |
Top Players
Catchers by Overturn Rate
All catchers →Min 20 challenges
| # | Name | Rate | Chall |
|---|---|---|---|
| 1 |  J.T. Realmuto PHI | 79.5% | 78 |
| 2 |  Carson Kelly CHC | 70.8% | 89 |
| 3 | 70.8% | 65 | |
| 4 |  Hunter Goodman COL | 68.2% | 107 |
| 5 |  Tyler Stephenson CIN | 67.7% | 133 |
Batters by Overturn Rate
All batters →Min 10 challenges
| # | Name | Rate | Chall |
|---|---|---|---|
| 1 | 70.8% | 24 | |
| 2 |  Kevin McGonigle DET | 65.5% | 29 |
| 3 |  Cal Raleigh SEA | 63.6% | 22 |
| 4 | 61.9% | 21 | |
| 5 |  Mark Vientos NYM | 60.0% | 25 |
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 →