John Libka
24 games graded behind the plate.
3,424 correct of 3,650 graded takes (93.8% ± 0.8, 95%). Best game 96.2% · worst 90.6%. 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 John Libka
This season is 3,650 graded takes, which puts John Libka's overall accuracy at 93.8% ± 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 730 takes, so ±1.7 points. (the league-wide two-strike effect is about 1 point in 2026.)
- any single corner of the zone — about 304 takes, so ±2.7 points. (corner cells are where umpires actually differ.)
- whether one pitcher is called tighter than another — about 61 takes, so ±6.0 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 88 pitches players chose to challenge, which are the pitches they already believed were wrong. 88 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
Sixteen and Calling Games
John Libka came up through the MHSAA Legacy Program with his father as mentor. His major-league debut came in 2017.
A Father's Classroom
John Libka was 16 when he started calling games. He came up through the MHSAA Legacy Program, which pairs high school students with experienced officials, and his mentor was his father, Gary Libka — a veteran official who had umpired for over thirty years. The program gave a teenager from Mayville, Michigan, a place on the field, paired with the man who knew the job best. That was where it started, in 2003.
John was born in Saginaw on June 13, 1987. He grew up in Mayville and attended Juniata Christian School in Vassar before graduating from the Wendelstedt Umpiring School in 2010, the step that moved him into professional baseball.
During a game in Fort Wayne in 2012, Libka and his umpiring partner dealt with three ejections in a postgame incident. The umpires were commended for how they handled the situation, which Libka cited as a key learning experience.
The Big Leagues
His first Major League game came on May 27, 2017. Five years later, in 2022, MLB promoted him to the full-time Major League umpiring staff. Three years after that promotion, he was assigned to his first League Championship Series. He also joined the UMPS CARE Charities Board of Directors as a Director at Large in 2025.
Libka umpires in 2026. We have graded him behind the plate in 18 games this season, and that record is what puts his name on this page.
Reporting: Retrosheet, MLB.com, MLive.com, MHSAA.com, UMPS CARE Charities. 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 |
|---|---|---|---|---|
| BAL @ COL2026-09-01 | B+ | 1.5 BAL | 3/5 | Two dugouts, and only one of them smiling. |
| SF @ BOS2026-08-21 | B+ | 0.5 SF | 3/5 | A workmanlike night — nothing to frame, nothing to fix. |
| MIA @ CIN2026-08-16 | A | 0.7 MIA | 2/6 | Reliable as a Tuesday: no complaints, no headlines. |
| CLE @ DET2026-08-12 | C+ | 0.7 DET | 6/8 | Hawkeye did more talking than the umpire tonight. |
| BAL @ TEX2026-08-07 | A | 0.1 TEX | 0/2 | The catcher barely had to sell a thing. |
| PIT @ MIL2026-08-03 | B | 0.0 MIL | 2/5 | A small strike zone, generously enforced for the offense. |
| MIA @ HOU2026-07-22 | B+ | 0.3 HOU | 2/5 | Nothing that'll trend, and on this beat that's a compliment. |
| WSH @ ATH2026-07-17 | B+ | 0.7 ATH | 3/6 | Reliable as a Tuesday: no complaints, no headlines. |
| NYM @ TOR2026-07-01 | A- | 0.1 TOR | 0/1 | An honest evening's grade: nothing loud, nothing missed by much. |
| KC @ CWS2026-06-27 | B+ | 0.3 CWS | 1/3 | A steady night's work behind the plate. |
| BAL @ LAA2026-06-22 | B- | 0.1 LAA | 1/4 | Pitchers earned every strike the hard way. |
| COL @ CHC2026-06-17 | B+ | 0.8 CHC | 2/3 | Down the middle. Both dugouts had the same zone. |
| ATH @ CHC2026-06-03 | B+ | 0.3 CHC | 1/2 | Squeezed the edges; the hitters didn't mind at all. |
| TEX @ LAA2026-05-24 | B+ | 0.1 LAA | 1/1 | A steady night's work behind the plate. |
| PIT @ STL2026-05-20 | A | 0.2 STL | 0/4 | Solid and unspectacular — exactly what the job asks. |
| CHC @ ATL2026-05-14 | B | 0.6 CHC | 2/2 | A steady night's work behind the plate. |
| TB @ BOS2026-05-10 | B+ | 1.4 TB | 3/5 | The strike zone picked a side, and wasn't shy about it. |
| CWS @ SD2026-05-03 | A- | 0.8 CWS | 2/5 | Called a fair game and let the players decide it. |
| KC @ ATH2026-04-29 | A- | 0.0 ATH | 0/1 | An honest evening's grade: nothing loud, nothing missed by much. |
| NYY @ BOS2026-04-23 | A | 0.5 NYY | 1/3 | A steady night's work behind the plate. |
| ATL @ PHI2026-04-17 | A- | 0.5 PHI | 1/3 | Reliable as a Tuesday: no complaints, no headlines. |
| WSH @ PIT2026-04-14 | B | 0.5 WSH | 3/6 | An honest evening's grade: nothing loud, nothing missed by much. |
| ATH @ NYM2026-04-10 | A | 0.0 NYM | 1/2 | Both benches went home with nothing to say — the rarest kind of night. |
| CIN @ MIA2026-04-06 | A- | 0.4 CIN | 0/1 | Called a fair game and let the players decide it. |