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Marlins · RP · Common · 2026
William Kempner
William Kempner's 2026 Legends Deck card is rated 55 overall using real 2026 Statcast pitching data (fastball velocity, spin, expected ERA, put-away rate). Ratings refresh nightly.
Source MLB Statcast dataThrough Rating refreshed nightly
55
RP
William Kempner
Marlins · 2026 · B:R T:R
ERA2.92
K14
WHIP0.97
Stock
Marketplace
Play free · no signup · 90 seconds
Face Kempner in a free half-inning
Play a half-inning in our Statcast-driven sim. William Kempner's real 2026 numbers are why this card is rated 55. No signup, about 90 seconds.
Overall Rating
Overall · out of 9955
Power76
Control84
Run prevention68
Durability39
Common · Miami Marlins · MLB lists: P
Pitching Stats (2026)
| G | GS | W | L | SV | IP | H | ER | BB | SO | K/9 | ERA | WHIP | BF |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 9 | 0 | 1 | 0 | 0 | 12.1 | 8 | 4 | 4 | 14 | 10.2 | 2.92 | 0.97 | 50 |
2026 MLB regular season, official MLB stats.
Transaction History
William Kempner appears in 2 archived official MLB transactions (1 trade), newest first. 1 of the trade lists William Kempner as a named side of a multi-player trade (the feed keys each trade row to one player).
| Date | Type | From | To | Details |
|---|---|---|---|---|
| Jan 15, 2025 | Trade | San Francisco Giants | Miami Marlins | San Francisco Giants traded RHP William Kempner to Miami Marlins for Future Considerations. International Bonus Pool Money. William Kempner was traded to Miami Marlins in this trade. Named inside the trade description above; the feed keys this row to one player only. |
| Jul 28, 2022 | Signed | — | San Francisco Giants | San Francisco Giants signed RHP William Kempner. |
From MLB’s official StatsAPI transactions feed (2011 to the current season, trades/signings/releases involving major-league clubs). Trade rows that name several players are keyed to one player by the feed; other players named in the trade are joined through its description, and same-name cases the feed cannot disambiguate are counted, not guessed. Browse the full archive.
Statcast (2026)
| xERA | 3.95 |
|---|---|
| xwOBA Against | 0.306 |
| Avg Fastball Velo | 95.5 mph |
| Put-Away Rate | — |
| Zone Rate | — |
| First-Pitch Strike | — |
Marketplace Price History
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Play a half-inning with cards like William Kempner
About 30 seconds. A loaner lineup against a CPU pitcher, real Statcast, no signup.
How this rating was calculated
Legends Deck rates every card using percentile-scaled Statcast data. William Kempner's current rating of 55 reflects their real 2026 season performance as of the last nightly refresh, not editorial opinion. When their actual Statcast numbers change, the card rating changes.
Full methodology: How Legends Deck card ratings work. Glossary: xwOBA, Statcast.
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