Pitcher · 2026
Mason Barnett
- Age
- 26
- B/T
- R/R
- Height
- 6' 0"
- Weight
- 218 lb
- Number
- #63
- Born
- November 7, 2000 in Kennesaw, GA, USA
- MLB debut
- August 30, 2025
- Drafted
- 2022, round 3
- College
- Auburn
- High school
- Cartersville
- dbWAR
- -.3 2 season(s)
- IP
- 34.0
- ERA
- 5.56
- FIP
- 5.70
- K/9
- 9.5
- FIP−
- 137 100 = avg
Mason Barnett is a relief pitcher for the Athletics. In 2026 he struck out 36 batters over 34.0 innings across 16 appearances, going 1-2. His ERA of 5.56 was 33.1% higher than the league average of 4.18 — 11th of 16 on his team, and 401st of 467 among MLB pitchers with 20+ innings. Stripping out defence, his 5.70 FIP suggests the ERA was no fluke. He missed bats on 24.2% of swings (10.8% of every pitch he threw), walked 11.6% of the batters he faced and struck out 24.5%. His -0.4 dbWAR is built from that FIP rather than runs allowed, so it credits him for what he controls and not for the defence behind him.
League context
Percentile among qualified pitchers, 2026.
Platoon splits
How left- and right-handed hitters fare against him.
| Split | PA | AB | H | HR | BB | SO | AVG | OBP | SLG | wOBA | K% |
|---|---|---|---|---|---|---|---|---|---|---|---|
| vs LHB | 70 | 62 | 17 | 4 | 8 | 12 | .274 | .357 | .548 | .385 | 17.1% |
| vs RHB | 77 | 66 | 13 | 4 | 9 | 24 | .197 | .312 | .409 | .322 | 31.2% |
Pitch sequencing
What Mason Barnett throws in each count, and what he follows each pitch with. Select any cell for the breakdown.
Select a count to see exactly what Mason Barnett throws in it.
Pitch arsenal
What he throws, how hard, and how often it misses in 2026.
| Four-Seam Fastball | 267 | 95.1 | 2,264 | 44.9% | 22.7% | |
| Slider | 132 | 87.4 | 2,505 | 54.5% | 30.3% | |
| Sweeper | 96 | 83.5 | 2,693 | 49.0% | 20.8% | |
| Curveball | 63 | 79.4 | 2,723 | 36.5% | 15.4% | |
| Changeup | 35 | 85.9 | 986 | 25.7% | 35.7% |
Pitching
Standard and advanced, by season.
| Trend | |||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2026 | 16 | 2 | 34.0 | 1 | 2 | 2 | 30 | 21 | 36 | 17 | 5.56 | 5.70 | 1.38 | 9.5 | 4.5 | 133 | 137 | -0.4 | |
| 2025 | 5 | 5 | 22.1 | 1 | 1 | 0 | 26 | 17 | 18 | 11 | 6.85 | 4.88 | 1.66 | 7.3 | 4.4 | 165 | 117 | 0.0 |
Head to head
Put Mason Barnett beside up to three others.
Similar players
Nearest 2026 seasons by command, run prevention and role, on rate statistics rather than totals.
wOBA uses linear weights measured from this season's own play-by-play rather than published constants, and wRC+ is park-adjusted against that same league. dbWAR is our own open implementation — not fWAR or bWAR — and the full derivation, including its simplifications, is on the methodology page.