Jim Wolf
24 games graded behind the plate.
3,374 correct of 3,621 graded takes (93.2% ± 0.8, 95%). Best game 96.7% · worst 88.1%. Grade is accuracy on taken pitches vs the rulebook zone; ABS is the Automated Ball-Strike System challenge record (how often the robots overruled the call).
What we can't say about Jim Wolf
This season is 3,621 graded takes, which puts Jim Wolf's overall accuracy at 93.2% ± 0.8 (95% interval). That is a real measurement against a league spanning about four points end to end. It is not enough for anything finer, and here is the arithmetic rather than our word for it:
- how the zone moves with two strikes — about 724 takes, so ±1.8 points. (the league-wide two-strike effect is about 1 point in 2026.)
- any single corner of the zone — about 302 takes, so ±2.8 points. (corner cells are where umpires actually differ.)
- whether one pitcher is called tighter than another — about 60 takes, so ±6.4 points. (a given pitcher is worked once or twice a season.)
And a note on the number itself: an accuracy figure is a rate plus a convention for what counts as a miss. Ours grades every taken pitch against the rulebook zone as the feed reports it. Others are more forgiving — UmpScorecards counts a call wrong only when the pitch was at least 90% likely to be a strike — so two sites can print the same percentage about the same umpire and not mean the same thing by it. How the grade is built.
The overturn rate is a different kind of number and does not belong beside the grade: it is accuracy on the 117 pitches players chose to challenge, which are the pitches they already believed were wrong. 117 is enough to print it with its own denominator, which is what we do — but it still ranks umpires by how often they are appealed, not by how often they are right.
The road to the plate
Jim Wolf
The man behind the plate for two of 2010's most memorable games, and the umpire who shared a field with his own brother.
Two Games in 24 Days
On May 9, 2010, Jim Wolf was behind the plate when Dallas Braden threw a perfect game. Less than a month later, he stood at second base for Armando Galarraga's near-perfect game — the one broken up by a call that became one of the most debated plays of the decade. Two of that season's most memorable pitching performances, and Wolf was on the field for both.
He reached the major league staff in 1999 after working through the Arizona Rookie League, the South Atlantic League, the California League, the Texas League, and the Pacific Coast League. He became a full-time member of the consolidated MLB umpiring staff in 2001 and wears uniform number 28. Born in West Hills, California, he graduated from El Camino Real High School before that long climb through the minor leagues.
The Brother on the Mound
Wolf is the older brother of former MLB pitcher Randy Wolf. In April 2001, the two became only the second set of brothers in modern baseball history to work the same major league game as umpire and player — Jim serving as third-base umpire, Randy on the mound at Wrigley Field. The arrangement required care: MLB removed Jim from assignments when his crew was scheduled to work a game involving Randy.
His postseason assignments include two World Series (2015 and 2019), five League Championship Series, and the 2010 All-Star Game.
Our grading record covers 17 of his games behind the plate this season.
Reporting: Wikipedia, Los Angeles Times, Baseball Reference Bullpen. Umpire data: MLB StatsAPI, via the Fever engine.
By the Desk · filed 2026-07-24 — the profile reads as of its filing; the grading record above is live · every fact in this piece comes from a sourced research pack and clears an independent fact-check, and nothing is edited after filing.
The games
| Game | Grade | Favor | ABS | Blue Note |
|---|---|---|---|---|
| AZ @ SF2026-08-29 | B- | 1.1 SF | 2/4 | Somebody's pitching staff sent a thank-you note. |
| MIN @ ATH2026-08-25 | B | 0.5 ATH | 6/8 | ABS had a long evening on this one. |
| AZ @ ATL2026-08-15 | C+ | 1.4 AZ | 2/5 | The zone leaned, and the ledger noticed. |
| CIN @ CWS2026-08-12 | A | 0.1 CIN | 3/6 | Nothing that'll trend, and on this beat that's a compliment. |
| HOU @ SD2026-08-07 | A | 0.5 HOU | 1/4 | The kind of night where the umpire is the least of the story. |
| MIN @ SEA2026-08-02 | B+ | 0.4 SEA | 0/2 | Called a fair game and let the players decide it. |
| NYY @ CWS2026-07-29 | B- | 0.4 NYY | 3/7 | A small strike zone, generously enforced for the offense. |
| PIT @ CLE2026-07-18 | B+ | 0.6 CLE | 2/5 | Reliable as a Tuesday: no complaints, no headlines. |
| CHC @ CIN2026-07-10 | B | 0.3 CHC | 5/9 | ABS had a long evening on this one. |
| ATH @ DET2026-07-07 | A- | 0.7 DET | 5/7 | ABS had a long evening on this one. |
| STL @ ATL2026-07-01 | A | 0.0 ATL | 0/1 | Reliable as a Tuesday: no complaints, no headlines. |
| TEX @ TOR2026-06-26 | B+ | 1.3 TOR | 1/5 | The strike zone picked a side, and wasn't shy about it. |
| NYY @ DET2026-06-22 | D | 0.2 DET | 4/6 | Generous with the corners — the pitchers said thank you. |
| BOS @ TB2026-06-10 | A | 0.1 TB | 2/4 | Nothing that'll trend, and on this beat that's a compliment. |
| CWS @ PHI2026-06-06 | B | 0.9 CWS | 2/3 | Corner-to-corner and then some. |
| MIA @ WSH2026-06-01 | B | 0.3 MIA | 5/8 | A few too many trips to the challenge cart. |
| TEX @ COL2026-05-20 | B- | 1.7 TEX | 4/5 | Somebody's pitching staff sent a thank-you note. |
| LAD @ LAA2026-05-15 | B+ | 1.0 LAD | 1/4 | The kind of night where the umpire is the least of the story. |
| SEA @ HOU2026-05-12 | B | 0.2 HOU | 3/6 | A small strike zone, generously enforced for the offense. |
| CIN @ PIT2026-05-01 | A- | 0.1 PIT | 3/5 | A steady night's work behind the plate. |
| LAA @ KC2026-04-24 | A | 1.2 KC | 3/6 | The grade leaned — the ledger says which way. |
| TOR @ AZ2026-04-18 | B- | 0.0 AZ | 0/0 | The zone stretched its legs. |
| CLE @ STL2026-04-13 | B+ | 1.1 CLE | 3/4 | The zone leaned, and the ledger noticed. |
| WSH @ CHC2026-03-28 | A- | 0.5 CHC | 3/3 | Nothing that'll trend, and on this beat that's a compliment. |