Dynasty
Nastiest GIFs
The List
Dynasty
Nastiest GIFs
The List

Justin Slaten

#63 - Relief Pitcher

Boston Red Sox

Bats / Throws Right / Right
Date of Birth 9/15/1997 (28)
Height, Weight 6'4", 222 lb
Hometown Longview, TX

2026 Season Stats

MLB Rank MLB Average
Sv IP ERA WHIP K% BB%
0 31.1 4.60 1.37 28.5% 5.8%
211th 3
Sv
230th 42.0
IP
226th 4.25
ERA
197th 1.35
WHIP
50th 22.5%
K%
31st 9.9%
BB%
FB MPH SwStr% CSW% Str-ICR MTK% PLV PLA
96.6 12.8% 29.1% 54.1% 5.5% 5.04 3.07
68th 94.6
FB MPH
129th 12.2%
SwStr%
147th 28.5%
CSW%
61st 51.1%
Str-ICR
242nd 4.7%
MTK%
89th 4.94
PLV
91st 3.48
PLA
Holds List
Rank
28th
Saves+Holds List
Rank
48th

Articles

8/13/2026Fantasy Baseball Relief Pitcher Roundup: 8/12Rick Graham

8/11/2026Fantasy Reliever Rankings: Closers, Holds & SOLDs - 8/11Rick Graham

8/9/2026Fantasy Baseball Relief Pitcher Roundup: 8/8Rick Graham

8/7/2026Fantasy Baseball Relief Pitcher Roundup: 8/6Rick Graham

8/4/2026Fantasy Reliever Rankings: Closers, Holds & SOLDs - 8/4Rick Graham

See More Articles
PL Pro logo Get PL Pro

Exclusive Access to:

Weekly Player Rater | Live Draft Assistant Tool
2026 Season Projections | Ad-Free Website

book icon Stats Glossary

Justin Slaten Overview

Hide 2026 MLB Percentile | Hide 2026 MLB Average
Year Team G GS IP W-L Sv Hld ERA WHIP xERA FIP xFIP PLA K% BB% H/9 HR/9 BABIP HR/FB% LOB% ICR% GB% SwStr% CSW% IPR% PLV
2024 BOS 44 0 55.1 6-2 2 13 2.93 1.01 2.77 2.60 2.96 2.67 25.9% 4.0% 7.6 0.65 .285 13.3% 70.6% 38.1% 50.6% 15.5% 29.3% 0.55 5.12
2025 BOS 36 0 34.0 2-4 3 7 4.24 1.09 3.30 3.69 4.34 2.41 18.2% 7.3% 7.1 0.79 .242 12.0% 54.9% 36.3% 43.1% 15.0% 27.9% 0.48 5.19
2026 BOS 36 0 31.1 2-4 0 17 4.60 1.37 3.01 3.02 3.13 3.07 28.5% 5.8% 10.1 1.15 .369 17.4% 61.5% 36.7% 46.1% 12.8% 29.1% 0.57 5.04
RP MLB Percentile 53 0 34 40-10 0 94 36 42 85 87 91 74 86 91 16 43 6 46 9 52 60 62 57 76 72
RP MLB AVG 33 2 42.0 2-2 3 6 4.25 1.35 4.23 4.26 4.30 3.48 22.5% 9.9% 8.3 1.14 .289 17.9% 72.6% 36.9% 43.6% 12.2% 28.5% 0.50 4.94
Career 116 0 120.2 10-10 5 37 3.73 1.13 2.98 3.02 3.39 2.70 24.5% 5.4% 8.1 0.82 .293 14.1% 63.6% 37.2% 47.2% 14.6% 28.9% 0.54 5.12

Justin Slaten Repertoire

2024 2025 2026 All
Hide MLB Percentile | Hide MLB Average

Justin Slaten Game Log

Justin Slaten Standard

Hide 2026 MLB Percentile | Hide 2026 MLB Average
Year Team G GS IP W-L QS Sv Hld P Strikes Balls TBF H 1B 2B 3B HR K BB HB WP
2024 BOS 44 0 55.1 6-2 0 2 13 811 546 265 224 47 36 6 1 4 58 9 2 4
2025 BOS 36 0 34.0 2-4 0 3 7 499 333 166 137 27 21 3 0 3 25 10 0 1
2026 BOS 36 0 31.1 2-4 0 0 17 508 341 167 137 35 25 6 0 4 39 8 0 0
RP MLB Percentile 53 0 34 40-10 0 0 94 33 35 72 35 46 39 44 44 46 51 84 81 72
RP MLB AVG 33 2 42.0 2-2 0 3 6 700 447 253 180 38 25 7 1 5 40 17 2 2
Career 116 0 120.2 10-10 0 5 37 1,818 1,220 598 498 109 82 15 1 11 122 27 2 5

Justin Slaten Advanced

Hide 2026 MLB Percentile | Hide 2026 MLB Average
Year Team K% BB% AVG SLG OPS wOBA BABIP BACON xAVG xwOBA xBABIP xwoBACON EV FB EV LA xERA
2024 BOS 25.9% 4.0% .223 .318 .577 .253 .285 .303 .214 .259 .264 .326 87.6 89.4 8.9 2.77
2025 BOS 18.2% 7.3% .214 .310 .580 .251 .242 .265 .231 .278 .261 .314 89.1 92.3 12.3 3.30
2026 BOS 28.5% 5.8% .276 .417 .736 .323 .369 .398 .219 .274 .289 .349 87.0 90.6 8.3 3.01
RP MLB Percentile 86 91 22 37 41 42 6 5 69 85 41 57 63 31 79 85
RP MLB AVG 22.5% 9.9% .240 .392 .715 .315 .289 .320 .236 .317 .280 .360 87.7 89.2 13.3 4.23
Career 24.5% 5.4% .235 .343 .621 .273 .293 .316 .220 .270 .269 .330 87.9 90.7 9.7 2.98

Justin Slaten Pitch › Mix

Hide 2026 MLB Percentile | Hide 2026 MLB Average
Year Team FF% (MPH) SI% (MPH) FC% (MPH) SL% (MPH) ST% (MPH) CB% (MPH) CH% (MPH) FS% (MPH) KN% (MPH) Fastball% Secondary%
2024 BOS29.2% (96.4)-37.7% (91.5)-24.5% (84.0)8.4% (84.3)--- 29.2% 70.7%
2025 BOS36.1% (96.7)-34.5% (92.7)-11.4% (85.1)18.0% (84.9)--- 36.1% 63.9%
2026 BOS25.2% (96.6)12.8% (97.3)41.5% (93.6)-17.1% (86.1)3.4% (84.6)--- 38.0% 62.0%
RP MLB Percentile 20 (79) 20 (90) 92 (96) - 44 (89) 8 (90) - - - 21.9% 79.3%
RP MLB AVG 38.1% (94.6) 26.4% (93.9) 20.3% (89.4) 25.5% (85.7) 21.4% (82.5) 16.3% (79.7) 17.1% (86.2) 17.3% (86.6) 32.6% (68.2) 48.1% 51.7%
Career30.0% (96.5)3.6% (97.3)37.9% (92.4)-18.9% (84.7)9.6% (84.6)--- 33.6% 66.4%

Justin Slaten Pitch › Results

Hide 2026 MLB Percentile | Hide 2026 MLB Average
Year Team FF CSW% SI CSW% FC CSW% SL CSW% ST CSW% CB CSW% CH CSW% FS CSW% KN CSW% Fastball CSW% Secondary CSW%
2024 BOS29.1% (33)-29.4% (40)-28.6% (42)32.4% (11)--- 29.1% 29.5%
2025 BOS26.1% (28)-33.1% (19)-28.1% (13)21.1% (15)--- 26.1% 28.8%
2026 BOS20.3% (16)32.3% (9)32.7% (18)-28.7% (18)41.2% (4)--- 24.4% 32.1%
RP MLB Percentile 9 (56) 80 (36) 82 (23) - 53 (31) 93 (52) - - - 16.2% 76.4%
RP MLB AVG 27.0% (25) 27.5% (10) 26.6% (12) 29.4% (21) 28.2% (16) 27.0% (11) 21.6% (15) 23.3% (17) 22.1% (9) 27.8% 28.8%
Career26.1% (77)32.3% (9)31.3% (77)-28.6% (73)27.4% (30)--- 26.7% 30.0%

Justin Slaten Batted Ball › Contact

Hide 2026 MLB Percentile | Hide 2026 MLB Average
Year Team GB% LD% FB% PU% SS% Pull% Cent% Oppo% Foul Str% PC% Fl&B% Solid% Brl% ICR%
2024 BOS 50.6% 20.8% 19.5% 9.1% 31.2% 44.2% 35.7% 20.1% 18.9% 61.6% 27.3% 7.1% 3.9% 38.1%
2025 BOS 43.1% 21.6% 24.5% 10.8% 33.3% 36.3% 42.2% 21.6% 18.4% 63.8% 21.6% 8.8% 5.9% 36.3%
2026 BOS 46.1% 23.6% 25.8% 4.5% 40.4% 37.8% 35.6% 26.7% 20.3% 62.9% 24.7% 7.9% 4.5% 36.7%
RP MLB Percentile 60 33 60 9 14 28 65 61 83 50 45 20 81 52
RP MLB AVG 43.6% 21.7% 24.6% 10.2% 34.9% 41.0% 33.8% 25.2% 18.2% 62.8% 24.4% 5.8% 7.1% 36.9%
Career 47.2% 21.7% 22.6% 8.4% 34.2% 40.2% 37.6% 22.3% 19.1% 62.6% 24.9% 7.8% 4.6% 37.2%

Justin Slaten Batted Ball › Outcomes

Hide 2026 MLB Percentile | Hide 2026 MLB Average
Year Team AVG wOBA BABIP BACON xAVG xwOBA xBABIP xwoBACON EV FB EV LA HR/FB ICR% IPA%
2024 BOS .223 .253 .285 .303 .214 .259 .264 .326 87.6 89.4 8.9 13.3% 38.1% 26.3%
2025 BOS .214 .251 .242 .265 .231 .278 .261 .314 89.1 92.3 12.3 12.0% 36.3% 27.0%
2026 BOS .276 .323 .369 .398 .219 .274 .289 .349 87.0 90.6 8.3 17.4% 36.7% 24.1%
RP MLB Percentile 22 42 6 5 69 85 41 57 63 31 79 46 52 52
RP MLB AVG .240 .315 .289 .320 .236 .317 .280 .360 87.7 89.2 13.3 17.9% 36.9% 24.5%
Career .235 .273 .293 .316 .220 .270 .269 .330 87.9 90.7 9.7 14.1% 37.2% 25.9%

Justin Slaten Approach › Plate Discipline

Hide 2026 MLB Percentile | Hide 2026 MLB Average
Year Team Zone% Str% Swing% O-Sw% Whiff% Foul Str% Con% Z-Con% O-Con% CS% SwStr% CSW% BIP% PLUS% IPR% Str-ICR
2024 BOS 46.6% 67.3% 53.5% 37.0% 29.0% 18.9% 71.0% 85.4% 46.3% 13.8% 15.5% 29.3% 19.1% 61.5% 0.55 52.8%
2025 BOS 49.7% 66.7% 53.9% 33.9% 27.9% 18.4% 72.1% 79.9% 55.3% 12.8% 15.0% 27.9% 20.4% 61.3% 0.48 51.9%
2026 BOS 49.4% 67.1% 50.8% 34.2% 25.2% 20.3% 74.8% 84.7% 55.7% 16.3% 12.8% 29.1% 17.7% 60.2% 0.57 54.1%
RP MLB Percentile 94 87 82 72 48 83 48 48 65 49 62 57 62 75 76 82
RP MLB AVG 44.5% 63.8% 47.4% 31.7% 25.6% 18.2% 74.4% 83.9% 58.5% 16.3% 12.2% 28.5% 17.1% 58.3% 0.50 51.1%
Career 48.2% 67.1% 52.9% 35.4% 27.7% 19.1% 72.3% 83.6% 51.1% 14.2% 14.6% 28.9% 19.1% 61.1% 0.54 52.9%

Justin Slaten Approach › Locations

Hide 2026 MLB Percentile | Hide 2026 MLB Average
Year Team Zone% aLoc% x-mLoc% gLoc% hiLoc% y-mLoc% loLoc% iLoc% oLoc% mmLoc%
2024 BOS 46.6% 22.5% 33.1% 44.4% 32.5% 19.1% 48.4% 29.8% 37.2% 6.2%
2025 BOS 49.7% 22.2% 32.5% 45.3% 30.7% 20.4% 48.9% 31.1% 36.5% 7.2%
2026 BOS 49.4% 28.7% 30.5% 40.7% 36.4% 22.4% 41.1% 30.9% 38.6% 9.1%
RP MLB Percentile 94 16 12 66 49 54 56 59 16 97
RP MLB AVG 44.5% 34.5% 27.0% 38.5% 36.4% 22.9% 40.7% 29.8% 43.1% 6.6%
Career 48.2% 24.2% 32.2% 43.6% 33.1% 20.4% 46.5% 30.4% 37.4% 7.3%

Justin Slaten Approach › Counts

Hide 2026 MLB Percentile | Hide 2026 MLB Average
Year Team Early% Behind% 2-Str% Early BIP% F-Str% TF-Str% ECS% 2-Str O-Sw% PAR%
2024 BOS 60.9% 10.5% 28.7% 18.0% 63.4% 48.2% 17.2% 26.6% 24.9%
2025 BOS 61.5% 12.2% 27.3% 16.0% 61.0% 45.6% 16.0% 28.7% 18.4%
2026 BOS 60.2% 10.2% 29.5% 18.0% 62.8% 50.4% 21.2% 32.0% 26.0%
RP MLB Percentile 76 80 47 90 64 51 53 88 95
RP MLB AVG 58.5% 12.2% 29.9% 14.4% 60.9% 50.1% 21.1% 26.8% 19.2%
Career 60.9% 10.9% 28.5% 17.4% 62.6% 48.1% 18.0% 28.7% 23.5%

Justin Slaten PLV

Hide 2026 MLB Percentile | Hide 2026 MLB Average
Year Team P PLV QP% AP% BP% Q-BP% MTK% HP HL PLA
2024 BOS 811 5.12 47.1% 19.1% 33.8% 13.3% 4.8% -3.8 +10 2.67
2025 BOS 499 5.19 49.5% 18.0% 32.5% 17.0% 4.2% -1.2 +3 2.41
2026 BOS 508 5.04 45.9% 20.5% 33.7% 12.2% 5.5% 2.6 +3 3.07
RP MLB Percentile 33 72 43 93 79 79 28 38 26 74
RP MLB AVG 700 4.94 45.9% 17.4% 36.7% 9.3% 4.7% 0.8 0 3.48
Career 1,818 5.12 47.4% 19.2% 33.4% 14.0% 4.8% -2.4 +17 2.70
Get Premium