Pitcher · 2025
Mason Thompson
- Age
- 27
- B/T
- R/R
- Height
- 6' 6"
- Weight
- 241 lb
- Number
- #98
- Born
- February 20, 1998 in Round Rock, TX, USA
- MLB debut
- June 22, 2021
- Drafted
- 2016, round 3
- High school
- Round Rock
- Salary, 2025
- $770,000
- dbWAR
- -.1 1 season(s)
- IP
- 10.2
- ERA
- 11.81
- FIP
- 5.67
- K/9
- 9.3
- FIP−
- 136 100 = avg
Mason Thompson is a relief pitcher for the Washington Nationals. In 2025 he struck out 11 batters over 10.2 innings across 14 appearances, going 1-1. His ERA of 11.81 was 184.1% higher than the league average of 4.16. Stripping out defence, his 5.67 FIP suggests he pitched better than his ERA shows. He missed bats on 21.6% of swings (8.8% of every pitch he threw), walked 20.0% of the batters he faced and struck out 18.3%. His -0.1 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, 2025.
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 | 27 | 19 | 7 | 0 | 8 | 6 | .368 | .556 | .684 | .506 | 22.2% |
| vs RHB | 33 | 29 | 9 | 1 | 4 | 5 | .310 | .394 | .448 | .374 | 15.2% |
Pitch sequencing
What Mason Thompson 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 Thompson throws in it.
Pitch arsenal
What he throws, how hard, and how often it misses in 2025.
| Sinker | 96 | 95.0 | 2,191 | 41.7% | 12.8% | |
| Slider | 80 | 84.9 | 2,187 | 42.5% | 27.6% | |
| Four-Seam Fastball | 44 | 94.8 | 2,203 | 47.7% | 25.0% | |
| Curveball | 12 | 82.1 | 2,396 | 25.0% | 25.0% |
Pitching
Standard and advanced, by season.
| Trend | |||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2025 | 14 | 0 | 10.2 | 1 | 1 | 0 | 16 | 14 | 11 | 12 | 11.81 | 5.67 | 2.63 | 9.3 | 10.1 | 284 | 136 | -0.1 | — |
Head to head
Put Mason Thompson beside up to three others.
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.