Zack Kelly
BOS • P • Throws R • 2026 Season
Value
Standard score (σ), not a percentile, vs all qualified pitchers — 0 = average, +1 = one standard deviation above the mean. Built from 5x5 category z-scores (like Baseball Monster).
Control & Efficiency
Strike-throwing and length profile — drives the Likely-QS / High-K/BB start flags. The bar under each stat is this pitcher's percentile vs 207 qualified MLB starters (100th = best — already direction-adjusted, so a low BB% or P/PA scores high).
Arsenal
Throwing hand and pitch mix (share of pitches thrown) — the traits the matchup ratings below weigh against each opponent's splits.
Season Stats
The big number is the actual stat. The bar below it is this pitcher's percentile vs 385 qualified MLB pitchers (≥30 IP) this season — 100th = best, direction-adjusted (a low ERA/WHIP/BB scores high).
Splits & Tendencies
How this pitcher fares by batter hand, venue, opponent lineup quality (elite→poor offenses), and over the last 30 days. Lower ERA/WHIP is better; OPS-against shows for the hand/venue splits. Hover a tag for the numbers.
| Split | IP | ERA | WHIP | K/9 | BB/9 | OPS-agst |
|---|---|---|---|---|---|---|
| vs LHB | 4.2 | — | 1.29 | 11.6 | 1.9 | .774 |
| vs RHB | 11.2 | — | 1.29 | 6.2 | 4.6 | .540 |
| Home | 10.2 | 2.53 | 1.13 | 6.8 | 2.5 | .551 |
Luck Factor
How much this pitcher's results are outrunning or trailing the quality of what actually happened — league-relative. Hover a meter for the inputs.
Game Log (17 games)
| Date | Opp | Dec | IP | H | R | ER | BB | SO | HR | P |
|---|---|---|---|---|---|---|---|---|---|---|
| May 19 | @ Kansas City Royals | - | 0.2 | 1 | 0 | 0 | 0 | 0 | 0 | 8 |
| May 14 | vs Philadelphia Phillies | - | 0.2 | 2 | 1 | 0 | 0 | 1 | 0 | 26 |
| May 12 | vs Philadelphia Phillies | - | 1 | 0 | 0 | 0 | 0 | 1 | 0 | 11 |
| May 10 | vs Tampa Bay Rays | - | 0.1 | 1 | 1 | 1 | 1 | 0 | 0 | 16 |
| May 6 | @ Detroit Tigers | - | 1 | 0 | 0 | 0 | 2 | 2 | 0 | 25 |
| May 3 | vs Houston Astros | L | 1 | 1 | 2 | 1 | 2 | 0 | 0 | 19 |
| May 1 | vs Houston Astros | - | 1.1 | 2 | 0 | 0 | 0 | 2 | 0 | 19 |
| Apr 28 | @ Toronto Blue Jays | - | 1 | 1 | 0 | 0 | 1 | 2 | 0 | 20 |
| Apr 26 | @ Baltimore Orioles | - | 0.1 | 0 | 0 | 0 | 0 | 0 | 0 | 4 |
| Apr 22 | vs New York Yankees | - | 1 | 0 | 0 | 0 | 0 | 2 | 0 | 11 |
| Apr 20 | vs Detroit Tigers | - | 1.2 | 1 | 0 | 0 | 0 | 1 | 0 | 27 |
| Apr 18 | vs Detroit Tigers | - | 1 | 1 | 0 | 0 | 0 | 0 | 0 | 19 |
| Apr 12 | @ St. Louis Cardinals | - | 2 | 1 | 1 | 1 | 0 | 2 | 1 | 23 |
| Apr 10 | @ St. Louis Cardinals | L | 0.2 | 2 | 2 | 2 | 1 | 0 | 0 | 18 |
| Apr 7 | vs Milwaukee Brewers | - | 0.2 | 0 | 0 | 0 | 0 | 0 | 0 | 11 |
| Apr 5 | vs San Diego Padres | - | 1 | 1 | 1 | 1 | 0 | 0 | 0 | 17 |
| Apr 4 | vs San Diego Padres | - | 1 | 0 | 0 | 0 | 0 | 1 | 0 | 9 |