Players · K · Pitcher · 2026 regular season
Merrill Kelly
- Age
- 38
- B/T
- R/R
- Height
- 6' 2"
- Weight
- 210 lb
- Number
- #29
- Born
- October 14, 1988 in Houston, TX, United States
- MLB debut
- April 1, 2019
- Drafted
- 2010, round 8
- College
- Arizona State
- High school
- Desert Mountain
- Salary, 2026
- $20M
Compare with…vs Cristopher Sánchezvs Ryne Nelsonvs Nick Lodolo
- dbWAR
- 14.4 Regular season, 10 season(s)
- IP
- 162.0
- ERA
- 4.94
- FIP
- 5.33
- K/9
- 6.3
- FIP−
- 127 100 = avg
Merrill Kelly is a starting pitcher for the Arizona Diamondbacks. In 2026 he struck out 113 batters over 162.0 innings across 29 appearances, 29 of them starts, going 10-14. His ERA of 4.94 was 18.3% higher than the league average of 4.18 — 12th of 16 on his team, and 399th of 539 among MLB pitchers with 20+ innings. Stripping out defence, his 5.33 FIP suggests that his ERA had some help behind him. He missed bats on 21.6% of swings (10.6% of every pitch he threw), walked 9.9% of the batters he faced and struck out 16.1%. 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 regular season.
WAR by season
Pitching Regular season
Standard and advanced, by season. Regular-season games only — postseason games are listed separately below.
| Trend | ||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2026 | AZ | 29 | 29 | 162.0 | 10 | 14 | 0 | 166 | 89 | 113 | 70 | 4.94 | 5.33 | 1.46 | 6.3 | 3.9 | 118 | 127 | -0.2 | |
| 2025 | AZ/TEX | 32 | 32 | 184.0 | 12 | 9 | 0 | 157 | 72 | 167 | 48 | 3.52 | 3.76 | 1.11 | 8.2 | 2.3 | 85 | 90 | 3.1 | |
| 2024 | AZ | 13 | 13 | 73.2 | 5 | 1 | 0 | 67 | 33 | 63 | 19 | 4.03 | 4.25 | 1.17 | 7.7 | 2.3 | 99 | 104 | 0.8 | |
| 2023 | AZ | 30 | 30 | 177.2 | 12 | 8 | 0 | 143 | 65 | 187 | 69 | 3.29 | 3.85 | 1.19 | 9.5 | 3.5 | 76 | 89 | 3.1 | |
| 2022 | AZ | 33 | 33 | 200.1 | 13 | 8 | 0 | 167 | 75 | 177 | 61 | 3.37 | 3.65 | 1.14 | 8.0 | 2.7 | 85 | 92 | 3.2 | |
| 2021 | AZ | 27 | 27 | 158.0 | 7 | 11 | 0 | 163 | 78 | 130 | 41 | 4.44 | 4.11 | 1.29 | 7.4 | 2.3 | 104 | 96 | 2.3 | |
| 2020 | AZ | 5 | 5 | 31.1 | 3 | 2 | 0 | 26 | 9 | 29 | 5 | 2.59 | 3.99 | 0.99 | 8.3 | 1.4 | 58 | 90 | 0.6 | |
| 2019 | AZ | 32 | 32 | 183.1 | 13 | 14 | 0 | 184 | 90 | 158 | 57 | 4.42 | 4.51 | 1.31 | 7.8 | 2.8 | 98 | 100 | 2.2 |
Batting Regular season
Standard and advanced, by season. Regular-season games only — postseason games are listed separately below.
Separate from the regular season
Postseason Postseason
Wild Card through World Series. These games are counted on their own: none of them are in the regular-season tables, career totals, league context, leaderboards or dbWAR on this page.
Postseason pitching
| Season | Team | Round | G | GS | IP | W | L | SV | H | ER | HR | BB | SO | ERA | WHIP | K/9 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2023 Post | AZ | Postseason total | 4 | 4 | 24.0 | 3 | 1 | 0 | 12 | 6 | 4 | 8 | 28 | 2.25 | 0.83 | 10.5 |
| NLDS | 1 | 1 | 6.1 | 1 | 0 | 0 | 3 | 0 | 0 | 2 | 5 | 0.00 | 0.79 | 7.1 | ||
| NLCS | 2 | 2 | 10.2 | 1 | 1 | 0 | 6 | 5 | 3 | 6 | 14 | 4.22 | 1.13 | 11.8 | ||
| World Series | 1 | 1 | 7.0 | 1 | 0 | 0 | 3 | 1 | 1 | 0 | 9 | 1.29 | 0.43 | 11.6 |
Box-score and rate statistics only. wOBA, wRC+, FIP and dbWAR are measured against a full league season, and a postseason is a few teams playing each other for a month, so they are not computed for October.
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 | 425 | 369 | 98 | 19 | 50 | 60 | .266 | .355 | .491 | .368 | 14.1% |
| vs RHB | 279 | 250 | 68 | 9 | 20 | 53 | .272 | .324 | .424 | .327 | 19.0% |
Pitch sequencing
What Merrill 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 Merrill Kelly throws in it.
Pitch arsenal
What he throws, how hard, how often it misses, and what hitters do with it.
| Four-Seam Fastball | 728 | 92.1 | 2,364 | 46.8% | 14.7% | 138 | .283 | 1.008 | |
| Changeup | 724 | 88.5 | 2,166 | 41.6% | 30.9% | 202 | .228 | .642 | |
| Cutter | 357 | 91.0 | 2,368 | 46.2% | 12.4% | 90 | .322 | .995 | |
| Curveball | 298 | 82.5 | 2,574 | 45.3% | 22.2% | 51 | .176 | .530 | |
| Slider | 268 | 86.3 | 2,314 | 36.2% | 33.6% | 76 | .289 | .730 | |
| Sinker | 246 | 92.4 | 2,236 | 41.1% | 8.1% | 66 | .318 | .873 |
Compare Merrill Kelly with…
Side by side with up to three others.
Or read one already written — Merrill Kelly against:
- Cristopher Sánchez2025 leaders
- Ryne Nelson2025 Arizona Diamondbacks
- Nick Lodolosimilar 2026 seasons
- Tarik Skubal2025 leaders
- Brandon Pfaadt2025 Arizona Diamondbacks
- Shane Biebersimilar 2026 seasons
- Logan Webb2025 leaders
- Ryan Johnsonsimilar 2026 seasons
- Paul Skenes2025 leaders
- Andrew Abbottsimilar 2026 seasons
- Garrett Crochet2025 leaders
- Ryan Feltnersimilar 2026 seasons
Similar players
Nearest 2026 seasons by command, run prevention and role, on rate statistics rather than totals.
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.