William Kempner | Miami Marlins
MLB Player
William Kempner
Miami MarlinsHeight6' 0"Weight222 lbsAge25Experience1st Season
0SVTied-261st
2.92ERA
14KTied-577th
0.97WHIP
Player Information
PositionRelief Pitcher
Jersey#71
Date of Birth18/6/2001
BirthplaceSan Jose, CA
Experience1st Season
Bats / ThrowsRight/Right
MLB Debut2026
StatusInjured/60
Next Game
More Miami Marlins Players
Season, Postseason & Career
| Split | GP | GS | CG | SHO | IP | H | R | ER | HR | BB | K |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Career | 9 | 0 | 0 | 0 | 12.1 | 8 | 4 | 4 | 1 | 4 | 14 |
Pitching by Season
| Season | GP | GS | W | L | W% | WAR | ERA | WHIP | IP | K | BB | K/BB | H | R | ER | SV | HLD | BLSV |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2026 | 9 | 0 | 1 | 0 | 1.000 | 0.2 | 2.92 | 0.97 | 12.1 | 14 | 4 | 3.5 | 8 | 4 | 4 | 0 | 0 | 0 |
| Career | 9 | 0 | 1 | 0 | 1.000 | -- | 2.92 | 0.97 | 12.1 | 14 | 4 | 3.5 | 8 | 4 | 4 | 0 | 0 | 0 |
Opponent Batting by Season
| Season | P | TBF | P-TBF | OBA | OOBP | OSLUG | OOPS | 2B | 3B | HR | TB | RBI | BH | SH | SF | IBB |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2026 | 199 | 50 | 3.980 | .182 | .280 | .295 | .575 | 2 | 0 | 1 | 13 | 4 | 2 | 0 | 0 | 0 |
| Career | 199 | 50 | 3.980 | .182 | .280 | .295 | .575 | 2 | 0 | 1 | 13 | 4 | 2 | 0 | 0 | 0 |
Expanded Pitching by Season
| Season | P/S | P/I | K/9 | QS | CG | SHO | GSC | GB | FB | G/F | IR | IRS | WP | BK | SB | CS | RSUP |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2026 | 0.0 | 16.1 | 10.2 | 0 | 0 | 0 | 0.0 | 9 | 21 | 0.4 | 5 | 0 | 0 | 0 | 1 | 0 | 0.0 |
| Career | 0.0 | 16.1 | 10.2 | 0 | 0 | 0 | 0.0 | 9 | 21 | 0.4 | 5 | 0 | 0 | 0 | 1 | 0 | 0.0 |
Game Log
| Game | Result | IP | H | R | ER | HR | BB | K | GB | FB | P | TBF | GSC | Dec | Rel | ERA |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
 vs CLE2026 Regular Season | L 4-1 | 2.0 | 3 | 2 | 2 | 0 | 0 | 3 | 2 | 3 | 42 | 9 | 0.0 | - | - | 2.92 |
 vs SEA2026 Regular Season | W 8-4 | 0.1 | 2 | 2 | 2 | 1 | 2 | 0 | 0 | 3 | 17 | 5 | 0.0 | - | - | 1.74 |
 @ ATH2026 Regular SeasonWeek 27 | W 12-5 | 1.0 | 0 | 0 | 0 | 0 | 0 | 1 | 1 | 1 | 10 | 3 | 0.0 | - | - | 0.00 |
 @ PHI2026 Regular SeasonWeek 24 | L 7-0 | 2.1 | 0 | 0 | 0 | 0 | 0 | 2 | 1 | 4 | 33 | 8 | 0.0 | - | - | 0.00 |
 vs ARI2026 Regular SeasonWeek 23 | W 8-0 | 2.0 | 0 | 0 | 0 | 0 | 2 | 3 | 1 | 2 | 36 | 8 | 0.0 | W(1-0) | - | 0.00 |
 vs TB2026 Regular SeasonWeek 23 | L 6-0 | 1.1 | 1 | 0 | 0 | 0 | 0 | 1 | 1 | 3 | 13 | 5 | 0.0 | - | - | 0.00 |
 @ NYM2026 Regular SeasonWeek 22 | L 10-1 | 1.1 | 2 | 0 | 0 | 0 | 0 | 3 | 0 | 3 | 28 | 6 | 0.0 | - | - | 0.00 |
| @ NYM2026 Regular SeasonWeek 22 | L 6-1 | 1.0 | 0 | 0 | 0 | 0 | 0 | 0 | 2 | 1 | 12 | 3 | 0.0 | - | - | 0.00 |
 vs BAL2026 Regular SeasonWeek 18 | L 9-7 | 1.0 | 0 | 0 | 0 | 0 | 0 | 1 | 1 | 1 | 8 | 3 | 0.0 | - | - | 0.00 |