MLB Ump Watch
Ump Watch, Which Umpires Tilted Totals in 2025
Published
Some zones are cathedrals and some are closets, and the hitters know which is which long before the numbers do. Our Retrosheet build keeps score anyway: 2025 rolling run factors per home-plate umpire, with 1.00 meaning perfectly neutral.
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.
Friendly skies for hitters
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
Brennan Miller runs the tightest environment in the sample, 0.863 across 73 games, where scoring has run about 14 percent below the league norm.
David Rackley (0.893 in 92 games) rounds out the pitching-friendly wing.
The board
The over-leaning end of the board, in one look:
| 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.