Zack Kelly
P | Bats/Throws: R/R | 6' 3" 231LBS | Age: 29
W L ERA G GS SV IP SO WHIP
2022 1 0 3.95 13 0 0 13.2 11 1.32
2023 0 0 3.86 8 0 0 9.1 6 1.61
2024 3 1 2.09 27 2 0 38.2 44 0.96
3 Seasons 4 1 2.77 48 2 0 61.2 61 1.14
G W-L ERA IP SO WHIP
2022 13 1-0 3.95 13.2 11 1.32
2023 8 0-0 3.86 9.1 6 1.61
2024 27 3-1 2.09 38.2 44 0.96
3 Seasons 48 4-1 2.77 61.2 61 1.14
MLB Percentile Rankings
Pitch Distribution

Statcast Statistics

Season Age Pitches Batted
Balls
Barrels Barrel % Barrel/PA Exit
Velocity
Max EV Launch
Angle
LA Sweet-
Spot %
XBA XSLG WOBA XWOBA XWOBACON HardHit% K% BB% ERA xERA
2022 27 222 44 3 6.8 5.1 85.0 109.2 12.6 29.5 .198 .343 .316 .260 .287 25.0 18.6 6.8 3.95 2.76
2023 28 181 26 2 7.7 4.7 89.5 109.9 8.7 30.8 .225 .381 .357 .362 .316 46.2 14.0 18.6 3.86 5.74
2024 29 619 93 9 9.7 5.8 85.7 112.5 10.1 32.3 .199 .367 .234 .284 .353 28.0 28.6 10.4 2.10 3.20
Player 1022 163 14 8.6 5.5 86.1 112.5 10.5 31.3 .203 .363 .273 .292 .329 30.1 23.8 10.9
MLB 7.0 4.8 88.5 122.4 12.3 33.1 .245 .406 .316 .315 .369 36.5 22.2 8.4
! Note: All figures in this table cover the period 2015-present.

Statcast Pitch Arsenal

Kelly relies on 4 pitches.
Four Seamer
(30.8%) ,
Sweeper
(25.4%) ,
Changeup
(24.8%) ,
Cutter
(19.0%) ,


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Pitch Tracking



Batted Ball Profile

Season GB % FB % LD % PU % Pull % Straight % Oppo % Weak % Topped % Under % Flare/Burner % Solid % Barrel % Barrel/PA
2022 45.5 31.8 13.6 9.1 36.4 40.9 22.7 9.1 31.8 31.8 13.6 4.5 6.8 5.1
2023 53.8 26.9 19.2 0.0 34.6 42.3 23.1 3.8 38.5 30.8 19.2 0.0 7.7 4.7
2024 52.7 23.7 16.1 7.5 34.4 45.2 20.4 9.7 39.8 20.4 18.3 2.2 9.7 5.8
Player 50.9 26.4 16.0 6.7 35.0 43.6 21.5 8.6 37.4 25.2 17.2 2.5 8.6 5.5
MLB 44.5 23.7 24.8 7.0 37.1 37.5 25.3 3.9 32.7 24.8 24.4 5.8 7.0 4.8
! Note: All figures in this table cover the period 2015-present.

Pitch Movement


How this works: Every pitch is affected by the forces of gravity, which means that every pitch drops on its way from the mound to the plate. These numbers are reported with gravity, which makes them larger and different than other pitch movement numbers you may have seen. Since gravity requires time, and slower pitches aren’t ‘better’ just because they have more time to move, the movement of a pitch is compared to ‘average’ movement by comparing it to other MLB pitch types within +/- 2 MPH and from within +/- 0.5 feet of extension and release.
Vertical Movement (inches) Horizontal Movement (inches)
Year Pitch Team Hand # MPH Inches of Drop vs Avg % vs Avg Inches of Break vs Avg % Break vs Avg
2024 Sweeper BOS R 157 82.3 37.3 -0.6 -2 17.1 3.1 22
2024 4-Seam Fastball BOS R 190 96.2 14.8 -0.9 -6 10.0 2.2 28
2024 Changeup BOS R 153 83.5 39.0 3.9 11 17.9 3.7 26
2024 Cutter BOS R 117 90.4 27.3 -2.2 -9 2.4 0.1 5
2023 Slider BOS R 33 85.8 34.0 -1.5 -4 5.5 0.7 15
2023 Changeup BOS R 63 82.3 35.5 -0.5 -1 19.5 5.0 34
2023 4-Seam Fastball BOS R 83 94.5 15.4 -0.3 -2 11.7 4.1 53
2022 Slider BOS R 30 85.7 35.6 0.2 1 6.6 1.6 33
2022 Changeup BOS R 87 82.0 33.9 -1.2 -3 17.6 2.9 20
2022 4-Seam Fastball BOS R 105 94.6 15.0 -0.4 -3 11.2 3.5 45
! Note: Years are in reverse order.
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Run Values by Pitch Type

Year Pitch Type Team RV/100 Run Value Pitches % PA BA SLG wOBA Whiff% K% PutAway % xBA xSLG xwOBA Hard Hit %
2024 4-Seam Fastball 0.7 1 190 30.7 55 .190 .262 .333 19.8 23.6 17.6 .264 .512 .415 37.9
2024 Sweeper 4.1 6 157 25.4 38 .108 .216 .175 38.6 36.8 24.1 .126 .218 .160 17.4
2024 Changeup 0.3 0 153 24.7 31 .129 .355 .227 33.8 45.2 25.5 .151 .350 .209 11.8
2024 Cutter 3.0 4 117 18.9 28 .185 .296 .225 24.5 10.7 21.4 .255 .365 .282 37.5
2023 4-Seam Fastball -0.1 0 84 46.4 21 .286 .429 .438 14.7 9.5 10.5 .273 .500 .450 66.7
2023 Changeup -1.3 -1 63 34.8 16 .167 .333 .331 34.6 18.8 11.1 .126 .249 .291 11.1
2023 Slider 2.9 1 34 18.8 6 .167 .333 .208 21.4 16.7 16.7 .315 .369 .298 60.0
2022 4-Seam Fastball 1.6 2 105 47.3 27 .167 .208 .240 11.6 14.8 17.4 .168 .190 .194 23.8
2022 Changeup -2.5 -2 87 39.2 23 .333 .524 .398 20.5 26.1 19.4 .191 .360 .276 20.0
2022 Slider -5.3 -2 30 13.5 9 .333 .778 .461 26.7 11.1 33.3 .291 .691 .416 37.5
! Note: Years are in reverse order.
! Note: To better align with other values, positive numbers (red) are good, and negative numbers (blue) are poor.
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Spin Direction

Year Pitch Type Pitches MPH Active Spin % Total Movement (In.) Spin-Based Observed Deviation
2024 Changeup 153 83.5 94 18.9 3:00 3:15 -15
2024 Cutter 116 90.3 45 6.1 12:00 11:15 45
2024 4-Seam Fastball 190 96.2 96 17.7 1:15 1:15 0
2024 Sweeper 157 82.3 56 18.3 8:30 9:15 -45
2023 Changeup 63 82.3 91 20.8 3:00 2:45 15
2023 4-Seam Fastball 77 94.6 96 19.3 1:15 1:15 0
2023 Slider 31 85.7 38 6.6 10:15 9:45 30
2022 Changeup 86 81.9 85 19.3 3:00 2:30 30
2022 4-Seam Fastball 105 94.6 98 19.2 1:15 1:15 0
2022 Slider 30 85.7 34 7.4 10:15 9:15 60
! Note: This table is showing data from the PITCHER perspective.
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Swing/Take

Runs
Year Team PA Pitches Heart Shadow Chase Waste All
2022 59 222 1 0 -3 -1 -2
2023 43 181 4 4 -5 -2 0
2024 152 617 9 9 -4 -2 12
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Plate Discipline

Season Pitches Zone % Zone Swing % Zone Contact % Chase % Chase Contact % Edge % 1st Pitch Strike % Swing % Whiff % Meatball % Meatball Swing %
2022 222 53.6 68.1 87.7 20.4 61.9 36.5 64.4 45.9 17.6 9.9 72.7
2023 181 42.5 61.0 76.6 26.0 74.1 42.5 46.5 40.9 23.0 7.2 61.5
2024 619 50.6 63.6 78.4 29.4 52.2 43.6 68.6 46.7 29.4 7.6 76.6
Player 1,022 49.8 64.2 80.4 26.9 58.0 41.9 63.9 45.5 25.8 8.0 73.2
MLB 48.6 67.0 82.0 28.4 57.9 42.6 61.0 47.2 24.8 7.3 76.2
! Note: All figures in this table cover the period 2015-present.

Percentile Rankings

Year xwOBA /
xERA
xBA xSLG xISO xOBP Brl Brl% EV Hard
Hit%
K% BB% Whiff% Chase
Rate
FB
Velo
FB
Spin
CB
Spin
Extension
2022 63 29 79
2023 58 29 88
2024 79 92 69 34 79 57 16 97 99 86 22 78 60 85 29 91
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Expected Home Runs

Year Team Avg HR Trot Actual HR xHR HR-xHR Doubters Mostly Gone No Doubters No Doubter %

Expected Home Runs by Park

Year HR

Year to Year Changes

Metric 2022 2023 +/-   2024 +/-  
Fastball Velocity 94.6 94.5 -0.1 94.0 -0.5
Offspeed Velocity 82.0 82.3 0.3 83.5 1.2
Breaking Velocity 85.7 85.9 0.2 82.3 -3.6
Exit Velocity 85.0 89.5 4.5 85.7 -3.8
Launch Angle 12.6 8.7 -3.9 10.1 1.4
Barrel % 6.8 7.7 0.9 9.7 2.0
Hard Hit % 25.0 46.2 21.2 28.0 -18.2
LA Sweet-Spot % 29.5 30.8 1.3 32.3 1.5
xBA .198 .225 0.027 .199 -0.026
BA .259 .219 -0.040 .153 -0.066
xwOBA .260 .362 0.102 .284 -0.078
wOBA .316 .357 0.041 .234 -0.123
xSLG .343 .381 0.038 .367 -0.014
SLG .426 .375 -0.051 .277 -0.098
K% 18.6 14.0 -4.6 28.6 14.6
BB% 6.8 18.6 11.8 10.4 -8.2
Swing % 45.9 40.9 -5.0 46.7 5.8
Whiff% 17.6 23.0 5.4 29.4 6.4
In Zone % 53.6 42.5 -11.1 50.6 8.1
Out of Zone % 46.4 57.5 11.1 49.4 -8.1
Out of Zone Swing % 20.4 26.0 5.6 29.4 3.4
First Pitch Swing % 28.8 20.9 -7.9 30.7 9.8
First Pitch Strike % 64.4 46.5 -17.9 68.6 22.1
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Statcast Fielder Positioning

vs RHHvs LHH
YearAlignment TypePAwOBAPATotal%PATotal%
2022 Shifts 59 .316 32 4 12.5 27 22 81.5
2023 Shades 43 .357 19 0 0.0 24 7 29.2
2024 Shades 152 .234 83 10 12.0 69 36 52.2
! Note: Shifts are through the 2022 season, Shaded starting from the 2023 season, Shift: three or more infielders are on the same side of second base, Shade: positioned outside of their typical responsible slices of the field.
Learn more about how positioning is defined here

Pitch Tempo

Bases EmptyRunners On Base
SeasonTeamPitchesTempoFast %Slow %PitchesTempoFast %Slow %
2022 61 18.7 1.6% 1.6% 42 21.5 0.0% 0.0%
2023 38 16.5 10.5% 0.0% 44 20.8 0.0% 0.0%
2024 159 17.0 12.6% 0.0% 106 19.0 1.9% 2.8%
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Pitch Distribution