2026 Stats
W-L
0-0
ERA
0.00
WHIP
0.00
K
1
SV
0
Rest-of-Season Projections
Signed a one-year contract with the Marlins in March of 2026.
Sent back to minors
The Marlins optioned Kempner to Triple-A Jacksonville on Wednesday, Christina De Nicola of MLB.com reports.
Analysis
Kempner was summoned Tuesday from the minors and made his major-league debut in Miami's 9-7 loss to Baltimore with a perfect inning out of the bullpen. He'll make room on the roster for a fresh bullpen arm in Dax Fulton, who was called up from Jacksonville in a corresponding move.
Kempner was summoned Tuesday from the minors and made his major-league debut in Miami's 9-7 loss to Baltimore with a perfect inning out of the bullpen. He'll make room on the roster for a fresh bullpen arm in Dax Fulton, who was called up from Jacksonville in a corresponding move.
Pitching Stats
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2026 MLB Game Log
2026
Minor League Game Log
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Pitching Appearances Breakdown
Average Pitch Count
8
Last 10 Games
8
Last 5 Games
8
How many pitches does William Kempner generally throw?
1-10
11-20
21-30
31-40
41-50
51-60
61-70
71-80
81-90
91-100
101-110
111-120
121+
What part of the game does William Kempner generally pitch?
1st
2nd
3rd
4th
5th
6th
7th
8th
9th
Extra
% Games Reaching Innings Threshold
% Games By Number of Innings Pitched
Left/Right Pitching Splits
Since 2024
No Stats
2026
No Stats
| BAA | K | BB | H | HR | |
|---|---|---|---|---|---|
| Since 2024vs Left | .000 | 1 | 0 | 0 | 0 |
| Since 2024vs Right | .000 | 0 | 0 | 0 | 0 |
| 2026vs Left | .000 | 1 | 0 | 0 | 0 |
| 2026vs Right | .000 | 0 | 0 | 0 | 0 |
| 2025vs Left | 0 | 0 | 0 | 0 | 0 |
| 2025vs Right | 0 | 0 | 0 | 0 | 0 |
| 2024vs Left | 0 | 0 | 0 | 0 | 0 |
| 2024vs Right | 0 | 0 | 0 | 0 | 0 |
Home/Away Pitching Splits
Since 2024
No Stats
2026
No Stats
| ERA | WHIP | IP | K/9 | BB/9 | |
|---|---|---|---|---|---|
| Since 2024Home | 0.00 | 0.00 | 1.0 | 9.0 | 0.0 |
| Since 2024Away | 0 | 0 | 0 | 0 | 0 |
| 2026Home | 0.00 | 0.00 | 1.0 | 9.0 | 0.0 |
| 2026Away | 0 | 0 | 0 | 0 | 0 |
| 2025Home | 0 | 0 | 0 | 0 | 0 |
| 2025Away | 0 | 0 | 0 | 0 | 0 |
| 2024Home | 0 | 0 | 0 | 0 | 0 |
| 2024Away | 0 | 0 | 0 | 0 | 0 |
Minor League Left/Right Pitching Splits (AAA)
Since 2024
-34%
BAA vs LHP
2026
-17%
BAA vs LHP
| BAA | K | BB | H | HR | |
|---|---|---|---|---|---|
| Since 2024vs Left | .145 | 31 | 12 | 8 | 3 |
| Since 2024vs Right | .220 | 28 | 14 | 13 | 2 |
| 2026vs Left | .208 | 16 | 4 | 5 | 2 |
| 2026vs Right | .250 | 18 | 7 | 8 | 1 |
| 2025vs Left | .097 | 15 | 8 | 3 | 1 |
| 2025vs Right | .185 | 10 | 7 | 5 | 1 |
| 2024vs Left | 0 | 0 | 0 | 0 | 0 |
| 2024vs Right | 0 | 0 | 0 | 0 | 0 |
Stat Review
How does William Kempner compare to other relievers?
This section compares his stats with all relief pitcher seasons from the previous three seasons (minimum 30 innings)*. The bar represents the player's percentile rank. For example, if the bar is halfway across, then the player falls into the 50th percentile for that stat and it would be considered average.
* Exit Velocity, Barrels/BBE %, Balls Hit 95+ MPH %, and Spin Rate are benchmarked against 2019 data (min 30 IP). See here for more exit velocity/barrels stats plus an explanation of current limitations with that data set.
* Exit Velocity, Barrels/BBE %, Balls Hit 95+ MPH %, and Spin Rate are benchmarked against 2019 data (min 30 IP). See here for more exit velocity/barrels stats plus an explanation of current limitations with that data set.
K/BB
0.00K/9
9.0BB/9
0.0HR/9
0.0Fastball
97.4 mphERA
0.00WHIP
0.00BABIP
.000GB/FB
1.00Left On Base
0.0%Exit Velocity
91.5 mphBarrels/BBE
0.0%Spin Rate
2690 rpmBalls Hit 95+ MPH
0.0%Swinging Strike
12.5%Advanced Pitching Stats
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Defensive Stats
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Stats Vs Today's Lineup
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More Fantasy News
Recalled from Triple-A
The Marlins recalled Kempner from Triple-A Jacksonville on Tuesday, Christina De Nicola of MLB.com reports.
Analysis
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Sent to Triple-A
The Marlins optioned Kempner to Triple-A Jacksonville on Sunday.
Analysis
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Joins 40-man roster
The Marlins selected Kempner's contract from Triple-A Jacksonville on Tuesday.
Analysis
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Traded to Miami
The Marlins acquired Kempner from the Giants on Wednesday in exchange for international bonus pool space, Justice delos Santos of The San Jose Mercury News reports.
Analysis
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Heads to Giants in Round 3
The Giants have selected Kempner with the 106th overall pick in the 2022 first-year player draft.
Analysis
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