Players · K · Pitcher · 2026 regular season

Stephen Kolek

Kansas City Royals American League Central

Age: 29
B/T: R/R
Height: 6' 3"
Weight: 210 lb
Number: #32

Born: April 18, 1997 in Houston, TX, United States
MLB debut: March 21, 2024
Drafted: 2018, round 11
College: Texas A&M
High school: Shepherd

Compare with…vs Bailey Ober vs Cody Bradford vs Janson Junk

dbWAR: 2.8
IP: 54.0
ERA: 4.50
FIP: 4.55
K/9: 5.7
FIP−: 109

Stephen Kolek is a starting pitcher for the Kansas City Royals. In 2026 he struck out 34 batters over 54.0 innings across 10 appearances, 10 of them starts, going 4-3. His ERA of 4.50 was 7.6% higher than the league average of 4.18 — 12th of 19 on his team, and 346th of 539 among MLB pitchers with 20+ innings. Stripping out defence, his 4.55 FIP suggests the ERA was no fluke. He missed bats on 19.8% of swings (9.6% of every pitch he threw), walked 5.4% of the batters he faced and struck out 15.2%. His 0.5 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.

FIP4.55

K/95.7

WHIP1.24

WAR.5

WAR by season

Pitching Regular season

Standard and advanced, by season. Regular-season games only.


2026	KC	10	10	54.0	4	3	55	27	34	12	4.50	4.55	1.24	5.7	2.0	108	109	0.5
2025	SD/KC	19	19	112.2	5	7	98	44	77	31	3.51	3.82	1.14	6.2	2.5	85	92	1.8
2024	SD	42	0	46.2	3	0	59	27	39	12	5.21	3.57	1.52	7.5	2.3	128	88	0.6

Platoon splits

How left- and right-handed hitters fare against him.

Season

Opponent batting by the side the hitter bats from, 2026. Counted from play-by-play, so totals can differ from the box-score season line by a plate appearance or two.
Split	PA	AB	H	HR	BB	SO	AVG	OBP	SLG	wOBA	K%
vs LHB	126	121	33	4	5	24	.273	.302	.455	.328	19.0%
vs RHB	98	89	22	4	7	10	.247	.316	.438	.332	10.2%

Pitch sequencing

What Stephen Kolek throws in each count, and what he follows each pitch with. Select any cell for the breakdown.

ShowBatter

Four-seamSinkerSliderChangeupCutterSweeper

Select a count to see exactly what Stephen Kolek throws in it.

Pitch arsenal

What he throws, how hard, how often it misses, and what hitters do with it.

Season


Four-Seam Fastball	28.3%	237	94.2	2,241	47.7%	18.6%	41	.244	.686
Sinker	21.7%	182	93.7	2,211	36.3%	5.6%	59	.322	.900
Slider	16.4%	137	85.6	2,508	48.2%	42.9%	42	.167	.556
Cutter	12.3%	103	90.3	2,418	53.4%	20.8%	21	.190	.810
Changeup	11.9%	100	87.1	1,489	34.0%	16.0%	30	.300	.644
Sweeper	9.3%	78	79.9	2,571	33.3%	9.1%	18	.333	.980

Stephen Kolek's arsenal by usage. Velocity is average release speed in mph, spin in rpm, and whiff rate is misses per swing — the cleanest single measure of whether a pitch beats hitters. BAA and OPS are what hitters did against each pitch, credited to the one that ended the plate appearance, and are left blank under 15 at-bats.

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Similar players

Nearest 2026 seasons by command, run prevention and role, on rate statistics rather than totals.

Bailey OberMIN

ERA: 4.47
FIP: 4.61
SO: 96
WAR: 0.9

Very close

Janson JunkMIA

ERA: 4.22
FIP: 4.14
SO: 89
WAR: 1.5

Very close

Michael McGreevySTL

ERA: 3.95
FIP: 4.23
SO: 115
WAR: 1.8

Very close

Tanner BibeeCLE

ERA: 4.36
FIP: 4.52
SO: 148
WAR: 1.6

Very close

How these are computed

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.