Players · K · Pitcher · 2026
Zack Kelly
- Age
- 31
- B/T
- R/R
- Height
- 6' 3"
- Weight
- 231 lb
- Number
- #76
- Born
- March 3, 1995 in Roanoke, VA, United States
- MLB debut
- August 29, 2022
- College
- Newberry
- dbWAR
- .6 5 season(s)
- IP
- 16.1
- ERA
- 3.31
- FIP
- 3.65
- K/9
- 7.7
- FIP−
- 87 100 = avg
Zack Kelly is a relief pitcher for the Boston Red Sox. In 2026 he struck out 14 batters over 16.1 innings across 17 appearances, going 0-2. His ERA of 3.31 is 20.9% lower than the league average of 4.18. Stripping out defence, his 3.65 FIP suggests that his ERA had some help behind him. He missed bats on 21.1% of swings (9.2% of every pitch he threw), walked 9.9% of the batters he faced and struck out 19.7%. His 0.2 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 | 21 | 19 | 5 | 1 | 1 | 6 | .263 | .300 | .474 | .334 | 28.6% |
| vs RHB | 50 | 41 | 9 | 0 | 6 | 8 | .220 | .320 | .220 | .263 | 16.0% |
Pitch sequencing
What Zack Kelly throws in each count, and what he follows each pitch with. Select any cell for the breakdown.
Select a count to see exactly what Zack Kelly throws in it.
Pitch arsenal
What he throws, how hard, how often it misses, and what hitters do with it.
| Cutter | 124 | 90.6 | 2,476 | 46.0% | 21.2% | 27 | .259 | .762 | |
| Sweeper | 62 | 81.6 | 2,614 | 40.3% | 28.6% | 16 | .188 | .375 | |
| Sinker | 48 | 95.9 | 2,183 | 33.3% | 10.5% | 10 | — | — | |
| Four-Seam Fastball | 39 | 96.1 | 2,189 | 53.8% | 18.2% | 7 | — | — | |
| Changeup | 10 | 83.6 | 2,080 | 20.0% | 50.0% | 0 | — | — |
Head to head
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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.