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.
The sample covers 73 umpires with enough games behind the plate to matter, and the environments range from roughly 12 percent above league average at one end to 14 percent below at the other.
Where the runs flowed
The friendliest zone belongs to Mark Wegner, 1.125 over 71 games calling balls and strikes, where scoring has run about 12 percent above the league norm.
Adrian Johnson is right behind at 1.101 over 89 games.
Dan Bellino (1.097 in 96 games) keeps the trend company.
Where runs go to die
At the other extreme, Brennan Miller has squeezed scoring hardest: a 0.863 factor over 73 games, where scoring has run about 14 percent below the league norm.
Close behind on the low end: David Rackley, 0.893 across 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 |
The fine print
Because every factor rides a rolling three-season window, the board moves slowly and honestly: no single series, however strange, can rewrite it.
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.