P | Seattle Mariners
Bats/Throws: R/R | 6' 4" 215 lbs | Age: 28
Draft: 2019 | Rd. 1, No. 20, Seattle Mariners | Elon University
W L ERA G GS SV IP SO WHIP
2024 14 11 3.53 33 33 0 191 179 1.07
2025 10 8 4.21 23 23 0 126 137 1.19
2026 1 0 1.50 1 1 0 6 6 0.67
5 Seasons 46 34 3.57 113 113 0 643.2 627 1.11
G W-L ERA IP SO WHIP
2024 33 14-11 3.53 191 179 1.07
2025 23 10-8 4.21 126 137 1.19
2026 1 1-0 1.50 6 6 0.67
5 Seasons 113 46-34 3.57 643.2 627 1.11
MLB Percentile Rankings
Movement Profile (Induced Break)
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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 24 2092 382 34 8.9 6.3 89.3 111.5 11.3 31.4 .230 .390 .302 .287 .358 38.7 24.5 4.1 3.39 3.32
2023 25 2825 560 42 7.5 5.5 89.2 115.6 12.4 32.0 .258 .427 .284 .305 .382 40.9 22.7 2.5 3.35 3.90
2024 26 2967 568 46 8.1 5.9 89.0 113.9 14.8 30.5 .232 .403 .287 .290 .360 36.3 23.0 3.0 3.53 3.39
2025 27 2086 351 30 8.5 5.7 90.6 113.3 11.7 35.3 .249 .399 .300 .306 .386 43.9 26.1 5.5 4.21 3.88
2026 28 90 13 0 0.0 0.0 85.7 107.6 9.8 23.1 .207 .249 .235 .273 .297 38.5 27.3 9.1 1.50 3.04
Player 10060 1874 152 8.1 5.8 89.4 115.6 12.8 32.0 .242 .406 .292 .297 .371 39.6 23.9 3.6
MLB 7.2 4.9 88.6 122.9 12.4 33.3 .243 .408 .315 .316 .369 37.0 22.2 8.4
! Note: All figures in this table cover the period 2015-present.

Statcast Pitch Arsenal

Kirby relies on 6 pitches.
Four Seamer
(45.6%) ,
Knuckle Curve
(17.8%) ,
Sinker
(14.4%) ,
Slider
(11.1%) ,
Changeup
(7.8%) ,
Cutter
(3.3%) ,


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Pitch Tracking



Batted Ball Profile

AIR: Fly Balls + Line Drives + Popups All Batted Balls Batted Ball Breakdown
Season GB % AIR % FB % LD % PU % Pull % Straight % Oppo % Pull GB % Straight GB % Oppo GB % Pull AIR % Straight AIR % Oppo AIR %
2022 46.3 53.7 25.7 21.2 6.8 31.4 40.3 28.3 18.1 20.7 7.6 13.4 19.6 20.7
2023 44.6 55.4 25.7 22.1 7.5 38.2 31.4 30.4 22.3 16.1 6.3 15.9 15.4 24.1
2024 42.8 57.2 26.6 21.3 9.3 33.1 36.6 30.3 21.1 16.5 5.1 12.0 20.1 25.2
2025 44.4 55.6 23.4 26.8 5.4 33.6 37.6 28.8 20.2 17.7 6.6 13.4 19.9 22.2
2026 61.5 38.5 30.8 7.7 0.0 46.2 30.8 23.1 30.8 23.1 7.7 15.4 7.7 15.4
Player 44.5 55.5 25.6 22.5 7.5 34.5 36.0 29.6 20.8 17.5 6.2 13.7 18.5 23.3
MLB 44.2 55.8 24.0 24.7 7.1 37.4 37.4 25.1 20.6 17.6 5.9 16.7 19.7 19.3
! Note: All figures in this table cover the period 2015-present.

Quality of Contact

Season Weak % Topped % Under % Flare/Burner % Solid % Barrel % Barrel/PA
2022 3.1 35.3 24.1 22.3 5.8 8.9 6.3
2023 2.3 34.5 24.3 25.5 5.9 7.5 5.5
2024 3.3 33.1 27.8 21.7 5.8 8.1 5.9
2025 2.6 33.0 20.8 28.8 6.0 8.5 5.7
2026 7.7 30.8 23.1 23.1 7.7 0.0 0.0
Player 2.9 33.9 24.7 24.3 5.9 8.1 5.8
MLB 4.0 32.4 24.9 24.4 5.9 7.2 4.9
! Note: All figures in this table cover the period 2015-present.

Pitch Movement


How this works: This section shows two different ways to evaluate pitch movement. On the left, “Total Movement” shows the real-world movement of a pitch, including the forces of gravity, which affects every pitch thrown. Since gravity requires time, and slower pitches aren't 'better' just because they have more time to move, a pitch's movement is compared to other pitches of the same pitch type, within +/- 2 MPH and +/- 0.5 feet of extension/release. On the right, Induced Movement (or IVB) is reported without gravity, and attempts to isolate movement created by the pitcher's ability to spin and manipulate the ball.
Total Movement (in inches, w/ gravity)Induced Movement (in inches, w/o gravity)
YearPitchTeamHand#MPHVertical
Drop
vs.
Comparable
Horizontal
Break
vs.
Comparable
Vertical
Break
vs. AvgHorizontal
Break
vs. Avg
2026 4-Seam Fastball SEA R 41 96.0 15.4 -2.0 8.5ARM 0.9 14.6 -1.8 8.5ARM 0.5
2026 Changeup SEA R 7 87.9 29.0 -2.3 16.1ARM 1.7 6.7 -2.6 16.1ARM 1.3
2026 Cutter SEA R 3 92.1 22.3 1.2 1.1ARM -2.7 10.0 1.8 1.1ARM -3.3
2026 Curveball SEA R 16 82.9 54.8 3.6 9.3GLV 1.2 -14.4 3.7 9.3GLV 0.0
2026 Slider SEA R 10 86.0 40.9 4.6 12.1GLV 7.2 -3.4 4.6 12.1GLV 7.6
2026 Sinker SEA R 13 96.0 21.3 0.1 18.0ARM 2.0 8.7 -1.3 18.0ARM 2.1
2025 Changeup SEA R 43 87.8 29.3 -2.5 15.6ARM 1.1 6.1 -2.0 15.6ARM 1.1
2025 4-Seam Fastball SEA R 601 96.1 16.2 -2.1 10.1ARM 2.3 13.4 -2.4 10.1ARM 2.5
2025 Curveball SEA R 236 84.3 51.7 3.2 9.5GLV 2.1 -12.9 2.7 9.5GLV 0.5
2025 Slider SEA R 588 87.1 39.5 5.3 10.7GLV 6.3 -3.3 5.0 10.7GLV 6.3
2025 Sinker SEA R 559 96.3 20.6 -0.9 16.6ARM 1.3 9.0 -1.6 16.6ARM 1.5
2025 Split-Finger SEA R 59 86.0 35.3 1.7 11.7ARM 0.0 1.6 1.4 11.7ARM 0.5
! Note: Years are in reverse order.

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 %
2026 4-Seam Fastball 4.9 2 41 45.6 10 .100 .100 .090 22.7 30.0 25.0 .243 .260 .221 42.9
2026 Curveball 0.7 0 16 17.8 -- -- -- 0.0 -- 0.0 -- -- -- --
2026 Sinker 6.5 1 13 14.4 5 .000 .000 .175 25.0 40.0 33.3 .084 .095 .232 0.0
2026 Slider -17.3 -2 10 11.1 5 .333 1.333 .680 50.0 20.0 16.7 .136 .289 .386 50.0
2026 Changeup 4.2 0 7 7.8 2 .000 .000 .000 0.0 0.0 0.0 .321 .368 .296 50.0
2026 Cutter -1.0 0 3 3.3 -- -- -- 0.0 -- -- -- -- -- --
2025 4-Seam Fastball 1.1 7 601 28.8 153 .188 .341 .272 30.7 33.3 23.3 .210 .374 .292 42.5
2025 Slider 0.5 3 588 28.2 130 .276 .390 .287 31.1 25.4 17.9 .248 .403 .286 44.2
2025 Sinker -0.7 -4 559 26.8 159 .309 .496 .383 11.5 17.0 22.0 .292 .447 .357 42.6
2025 Curveball 0.8 2 236 11.3 61 .217 .267 .220 39.2 34.4 19.8 .229 .341 .251 48.7
2025 Split-Finger -4.7 -3 59 2.8 13 .333 .583 .485 38.7 30.8 16.0 .349 .519 .399 75.0
2025 Changeup 2.5 1 43 2.1 8 .125 .125 .113 5.0 12.5 9.1 .181 .200 .166 14.3
! Note: Years are in reverse order.
! Note: To better align with other values, positive numbers (red) are good, and negative numbers (blue) are poor.

Spin Direction

Year Pitch Type Pitches MPH Active Spin % Total Movement (In.) Spin-Based Observed Deviation
2026 4-Seam Fastball 41 96.0 92 16.6 1:15 1:00 15
2026 Knuckle Curve 16 82.9 83 19.9 7:15 7:00 15
2026 Sinker 13 96.0 90 20.4 1:15 2:15 -60
2026 Slider 10 86.0 59 14.2 7:15 8:15 -60
2025 Changeup 42 87.8 96 17.1 2:00 2:30 -30
2025 4-Seam Fastball 582 96.1 90 16.6 1:30 1:15 15
2025 Split-Finger 54 86.0 91 12.6 2:30 3:00 -30
2025 Knuckle Curve 213 84.1 82 18.1 7:15 7:00 15
2025 Sinker 535 96.2 87 19.2 1:30 2:15 -45
2025 Slider 557 87.1 53 12.7 7:15 8:15 -60
! Note: Years are in reverse order.
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! Note: This table is showing data from the PITCHER perspective.
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Pitcher Arm Angle

! Note: Data is available from 2020 through the present.
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Statcast Pitching Run Value

Runs
Year Team PA Pitches Heart Shadow Chase Waste All
2022 542 2,092 4 10 -9 -5 0
2023 756 2,825 24 16 -8 -5 26
2024 777 2,967 8 31 -15 -10 15
2025 524 2,086 3 20 -11 -6 6
2026 22 90 1 1 0 -1 1
Player 2,621 10,060 40 79 -44 40 49
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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 2,092 55.0 71.9 81.4 29.1 71.2 45.6 67.7 52.6 21.2 8.7 84.1
2023 2,825 56.8 70.9 82.8 32.9 60.9 45.3 69.5 54.5 22.9 8.6 77.9
2024 2,967 52.0 73.2 82.1 31.9 60.7 44.7 66.3 53.4 24.1 8.0 83.5
2025 2,086 49.9 68.4 82.9 29.8 51.4 44.1 64.7 49.0 26.7 7.2 75.3
2026 90 45.6 63.4 88.5 30.6 66.7 52.2 54.5 45.6 19.5 2.2 50.0
Player 10,060 53.5 71.2 82.3 31.1 60.8 45.0 67.1 52.6 23.6 8.1 80.3
MLB 48.9 67.0 82.5 28.4 58.0 42.7 61.1 47.3 25.0 7.4 76.3
! Note: All figures in this table cover the period 2015-present.

Percentile Rankings

Run Value Pitching
Year Pitching Fastball Breaking Off
Speed
xERA Fastball
MPH
Fastball
Spin
Curve
Spin
Avg
EV
Chase% Whiff% K% BB% Barrel% Hard-
Hit%
GB% Extension
2022 46 87 6 25 73 72 40 12 28 46 15 63 96 22 44 66 69
2023 98 97 91 62 61 85 45 30 43 88 27 43 100 58 38 64 47
2024 87 95 87 5 76 80 44 42 42 84 39 50 99 41 70 52 58
2025 63 61 78 36 53 80 45 21 14 68 61 76 89 47 21 61 55
2026 78 99 4 69 60 72 26 66 52 22 54 45 47 47 82 51
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Expected Home Runs

Adjusted

Year Team Avg HR Trot Actual HR xHR HR-xHR Doubters Mostly Gone No Doubters No Doubter %
2022 24.32 13 13.2 0 14 14 3 23.1
2023 22.76 22 21.2 1 12 18 8 36.4
2024 25.01 22 21.6 0 8 15 11 50.0
2025 24.32 19 15.0 4 9 8 9 47.4
2026 -- 1 0.4 1 0 1 0 0.0
Player 24.06 77 71.4 6 43 56 31 40.3
Note: xHR tells how many of this pitcher's batted balls allowed would have been out of other stadiums. The "Adjusted" view here accounts for different wall heights, distances and environmental effects using Statcast Park Factor data.
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Expected Home Runs by Park

Adjusted

Year HR
2022 13 9 12 16 14 13 16 9 8 9 9 18 16 11 15 18 14 10 11 15 11 13 24 15 8 8 18 20 13 13 11
2023 22 18 17 22 25 21 23 19 21 18 20 19 20 19 24 23 23 20 20 27 18 20 33 25 17 16 21 22 22 22 21
2024 22 23 19 23 20 23 25 21 17 15 21 23 24 19 22 19 20 19 23 23 25 23 28 26 17 21 21 21 25 21 22
2025 19 17 11 13 16 15 12 16 13 11 12 14 17 23 16 12 19 16 14 17 16 13 15 17 15 15 12 16 18 14 13
2026 1 0 0 1 0 1 0 0 1 0 0 1 0 1 1 0 0 0 0 1 0 1 1 1 0 0 0 1 1 0 0
Player 77 67 59 75 75 73 76 65 60 53 62 75 77 73 78 72 76 65 68 83 70 70 101 84 57 60 72 80 79 70 67
Note: xHR tells how many of this pitcher's batted balls allowed would have been out of other stadiums. The "Adjusted" view here accounts for different wall heights, distances and environmental effects using Statcast Park Factor data.
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Year to Year Changes

2026 +/-   2025 +/-   2024 +/-   2023 +/-   2022
Results
BA .105 -.147 .252 +.007 .245 -.001 .246 -.018 .264
xBA .207 -.042 .249 +.017 .232 -.026 .258 +.028 .230
OBP .227 -.073 .300 +.028 .272 +.002 .270 -.029 .299
xOBP .321 +.021 .300 +.037 .263 -.019 .282 +.014 .268
SLG .263 -.129 .392 -.001 .393 -.002 .395 +.002 .393
xSLG .249 -.150 .399 -.004 .403 -.024 .427 +.037 .390
ISO .158 +.018 .140 -.009 .149 .000 .149 +.020 .129
xISO .042 -.108 .150 -.021 .171 +.001 .170 +.010 .160
BABIP .083 -.232 .315 +.023 .292 -.001 .293 -.039 .332
wOBA .235 -.065 .300 +.013 .287 +.003 .284 -.018 .302
xwOBA .273 -.033 .306 +.016 .290 -.015 .305 +.018 .287
wOBAcon .232 -.145 .377 +.021 .356 +.002 .354 -.026 .380
xwOBAcon .297 -.089 .386 +.026 .360 -.022 .382 +.024 .358
BACON .154 -.191 .345 +.025 .320 -.001 .321 -.033 .354
xBACON .311 -.035 .346 +.039 .307 -.030 .337 +.026 .311
Statcast Hit Metrics
Hard Hit % 38.5 -5.4 43.9 +7.6 36.3 -4.6 40.9 +2.2 38.7
Avg Exit Velocity 85.7 -4.9 90.6 +1.6 89.0 -0.2 89.2 -0.1 89.3
Launch Angle Sweet-Spot % 23.1 -12.2 35.3 +4.8 30.5 -1.5 32.0 +0.6 31.4
Barrel % 0.0 -8.5 8.5 +0.4 8.1 +0.6 7.5 -1.4 8.9
Avg Launch Angle 9.8 -1.9 11.7 -3.1 14.8 +2.4 12.4 +1.1 11.3
Statcast Bat Tracking
Bat Speed 69.5 -2.2 71.7 +0.6 71.1 -0.5 71.6 -- --
Attack Angle 12° +4° -- --
Ideal Attack Angle % 54.3 +3.5 50.8 -0.7 51.5 +2.6 48.9 -- --
Attack Direction -5° -7° -1° -1° -- --
Swing Path - Tilt 34° +1° 32° +2° 31° -1° 32° -- --
Swing Length 7.1 0.0 7.1 0.0 7.1 0.0 7.1 -- --
Statcast Pitch Metrics
Fastball Velocity 95.8 -0.4 96.2 +0.2 96.0 0.0 96.0 +2.0 94.0
Breaking Velocity 84.1 -2.2 86.3 +0.1 86.2 +1.6 84.6 +1.9 82.7
Offspeed Velocity 87.9 +1.1 86.8 +0.8 86.0 +0.7 85.3 -0.7 86.0
Batted Ball Results
Barrels 0 -30 30 -16 46 +4 42 +8 34
Popup % 0.0 -5.4 5.4 -3.9 9.3 +1.8 7.5 +0.7 6.8
Flyball % 30.8 +7.4 23.4 -3.2 26.6 +0.9 25.7 0.0 25.7
Line Drive % 7.7 -19.1 26.8 +5.5 21.3 -0.8 22.1 +0.9 21.2
Groundball % 61.5 +17.1 44.4 +1.6 42.8 -1.8 44.6 -1.7 46.3
Pull % 46.2 +12.6 33.6 +0.5 33.1 -5.1 38.2 +6.8 31.4
Straight Away % 30.8 -6.8 37.6 +1.0 36.6 +5.2 31.4 -8.9 40.3
Opposite Field % 23.1 -5.7 28.8 -1.5 30.3 -0.1 30.4 +2.1 28.3
Weak Contact % 7.7 +5.1 2.6 -0.7 3.3 +1.0 2.3 -0.8 3.1
Pull Airball % 15.4 +2.0 13.4 +1.4 12.0 -3.9 15.9 +2.5 13.4
Topped Contact % 30.8 -2.2 33.0 -0.1 33.1 -1.4 34.5 -0.8 35.3
Under Contact % 23.1 +2.3 20.8 -7.0 27.8 +3.5 24.3 +0.2 24.1
Flare/Burner Contact % 23.1 -5.7 28.8 +7.1 21.7 -3.8 25.5 +3.2 22.3
Solid Contact % 7.7 +1.7 6.0 +0.2 5.8 -0.1 5.9 +0.1 5.8
HR/FB % 25.0 +6.7 18.3 +3.7 14.6 -0.7 15.3 +2.0 13.3
Popups 0 -19 19 -34 53 +11 42 +16 26
Flyballs 4 -78 82 -69 151 +7 144 +46 98
Line Drives 1 -93 94 -27 121 -3 124 +43 81
Groundballs 8 -148 156 -87 243 -7 250 +73 177
Plate Discipline
In Zone % 45.6 -4.3 49.9 -2.1 52.0 -4.8 56.8 +1.8 55.0
Out of Zone % 54.4 +4.3 50.1 +2.1 48.0 +4.8 43.2 -1.8 45.0
Edge % 52.2 +8.1 44.1 -0.6 44.7 -0.6 45.3 -0.3 45.6
Zone Swing % 63.4 -5.0 68.4 -4.8 73.2 +2.3 70.9 -1.0 71.9
Out of Zone Swing % 30.6 +0.8 29.8 -2.1 31.9 -1.0 32.9 +3.8 29.1
In Zone Contact % 88.5 +5.6 82.9 +0.8 82.1 -0.7 82.8 +1.4 81.4
Out of Zone Contact % 66.7 +15.3 51.4 -9.3 60.7 -0.2 60.9 -10.3 71.2
Whiff % 19.5 -7.2 26.7 +2.6 24.1 +1.2 22.9 +1.7 21.2
First Strike % 54.5 -10.2 64.7 -1.6 66.3 -3.2 69.5 +1.8 67.7
First Pitch Swing % 27.3 -9.0 36.3 -1.9 38.2 +0.7 37.5 -1.1 38.6
Swing % 45.6 -3.4 49.0 -4.4 53.4 -1.1 54.5 +1.9 52.6
Meatball Swing % 50.0 -25.3 75.3 -8.2 83.5 +5.6 77.9 -6.2 84.1
Meatball % 2.2 -5.0 7.2 -0.8 8.0 -0.6 8.6 -0.1 8.7
Zone Swing & Miss % 11.5 -5.6 17.1 -0.8 17.9 +0.7 17.2 -1.4 18.6
Out of Zone Swing & Miss % 33.3 -15.3 48.6 +9.3 39.3 +0.2 39.1 +10.3 28.8
In Zone 41 -1,000 1,041 -501 1,542 -62 1,604 +453 1,151
Out of Zone 49 -996 1,045 -380 1,425 +204 1,221 +280 941
Edge 47 -872 919 -408 1,327 +48 1,279 +326 953
In Zone Swings 26 -686 712 -417 1,129 -9 1,138 +311 827
Out of Zone Swings 15 -296 311 -144 455 +53 402 +128 274
In Zone Swing & Misses 3 -119 122 -80 202 +6 196 +42 154
Out of Zone Swing & Misses 5 -146 151 -28 179 +22 157 +78 79
Basic
Pitches 90 -1,996 2,086 -881 2,967 +142 2,825 +733 2,092
PA 22 -502 524 -254 778 +21 757 +215 542
AB 19 -461 480 -260 740 +13 727 +216 511
Hits 2 -119 121 -60 181 +2 179 +44 135
Singles 1 -84 85 -33 118 -4 122 +25 97
Doubles 0 -20 20 -18 38 +10 28 +5 23
Triples 0 -1 1 -2 3 -4 7 +5 2
Home Runs 1 -14 15 -7 22 0 22 +9 13
Walks 2 -27 29 +6 23 +4 19 -3 22
Strikeouts 6 -131 137 -42 179 +7 172 +39 133
K% 27.3 +1.2 26.1 +3.1 23.0 +0.3 22.7 -1.8 24.5
BB% 9.1 +3.6 5.5 +2.5 3.0 +0.5 2.5 -1.6 4.1
HBP 1 -6 7 0 7 +1 6 +1 5
Batted Balls 13 -338 351 -217 568 +8 560 +178 382
Number of Fastballs 57 -1,103 1,160 -560 1,720 -1 1,721 +261 1,460
Number of Offspeed 7 -95 102 -200 302 +80 222 +55 167
Number of Breaking 26 -798 824 -120 944 +64 880 +415 465
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Statcast Fielder Positioning

vs RHHvs LHH
YearAlignment TypePAwOBAPATotal%PATotal%
2022 Shifts 542 .302 258 61 23.6 284 165 58.1
2023 Shades 756 .284 403 32 7.9 353 192 54.4
2024 Shades 776 .288 421 72 17.1 355 213 60.0
2025 Shades 496 .287 231 29 12.6 265 116 43.8
2026 Shades 18 .171 4 0 0.0 14 8 57.1
! 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 566 16.5 28.1% 0.7% 310 25.3 0.0% 12.6%
2023 793 16.2 27.2% 0.1% 353 21.3 0.0% 0.6%
2024 818 17.3 5.0% 0.7% 384 20.6 0.0% 1.0%
2025 602 16.6 16.8% 0.3% 277 19.9 0.4% 0.4%

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Pitch Distribution