MLB Ump Watch
Ump Watch, Which Umpires Tilted Totals in 2025
Published
The archive keeps score on the men keeping score. These are the 2025 rolling-window run factors for home-plate umpires from our Retrosheet mirror, anything over 1.00 leaned toward offense, anything under leaned toward pitching.
All told, 73 umpires qualify for the board, and the gap between the extremes is real: about 12 percent above the norm at the top, 14 percent below at the bottom.
The offense-friendly zones
Mark Wegner owns the most hitter-friendly environment in the sample: a 1.125 run factor across 71 games behind the plate, where scoring has run about 12 percent above the league norm.
Next in line: Adrian Johnson, 1.101 across 89 games.
Dan Bellino (1.097 in 96 games) keeps the trend company.
Where runs go to die
The stingiest zone belongs to Brennan Miller: 0.863 over 73 games behind the plate, where scoring has run about 14 percent below the league norm.
David Rackley is nearly as stingy at 0.893 over 92 games.
By the numbers
Here are the top five run environments, highest factor first:
| Umpire | Run factor | Games |
|---|---|---|
| Mark Wegner | 1.125 | 71 |
| Adrian Johnson | 1.101 | 89 |
| Dan Bellino | 1.097 | 96 |
| Mike Muchlinski | 1.093 | 86 |
| Chris Guccione | 1.091 | 79 |
Worth remembering
Method matters here: each factor is a rolling three-season sample, so one wild week cannot vault a name to the top of the board, and a single quiet month cannot bury one.
Think of it as weather: nobody controls it, everybody plays in it, and only some people bother to check it before first pitch.
These are historical tendencies from seasons past, not tonight's assignments, treat them as trivia about the shape of the sport, not a betting signal on any specific game.