Players · B · 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, United States
- MLB debut
- August 30, 2025
- Drafted
- 2022, round 3
- College
- Auburn
- High school
- Cartersville
- dbWAR
- -.8 2 season(s)
- IP
- 50.0
- ERA
- 7.02
- FIP
- 6.66
- K/9
- 9.0
- FIP−
- 159 100 = avg
Mason Barnett is a relief pitcher for the Athletics. In 2026 he struck out 50 batters over 50.0 innings across 20 appearances, going 1-4. His ERA of 7.02 is 68.0% higher than the league average of 4.18 — the worst on his team, and 525th of 538 among MLB pitchers with 20+ innings. Stripping out defence, his 6.66 FIP suggests he pitched better than his ERA shows. He missed bats on 22.3% of swings (9.7% of every pitch he threw), walked 13.1% of the batters he faced and struck out 21.8%. His -0.9 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.
WAR by season
Pitching
Standard and advanced, by season.
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 | 120 | 101 | 30 | 6 | 18 | 18 | .297 | .400 | .535 | .404 | 15.0% |
| vs RHB | 109 | 95 | 23 | 8 | 12 | 32 | .242 | .339 | .516 | .372 | 29.4% |
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, how often it misses, and what hitters do with it.
| Four-Seam Fastball | 447 | 94.9 | 2,229 | 42.1% | 19.8% | 98 | .276 | .920 | |
| Slider | 162 | 87.3 | 2,503 | 53.7% | 26.3% | 29 | .241 | .767 | |
| Sweeper | 138 | 83.6 | 2,685 | 46.4% | 24.6% | 34 | .235 | .765 | |
| Curveball | 93 | 79.0 | 2,697 | 38.7% | 13.5% | 21 | .333 | 1.036 | |
| Changeup | 69 | 85.3 | 992 | 29.0% | 36.0% | 15 | .267 | .933 |
Head to head
Put Mason Barnett beside up to three others.
Or read one already written — Mason Barnett against:
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.