Stephen Kolek

RHP

Team: Kansas City RoyalsThrows: RHeight: 6'3"Weight: 210 lbDOB: Apr 18, 1997Born: Houston, TX, USAActive

Compare

Games

4.50

ERA

9.8%

K-BB%

94.2 mph

FB Velo

25.3%

CSW%

Stuff+

-9 vs MLB 100

vL 87▼vR 96

DLoc+

108

+8 vs MLB 100

vL 109▲vR 108▲

Stockyard PLoc+

104

+4 vs MLB 100

2026 Stockyard PLoc+ -> 2027

Pitching+

-4 vs MLB 100

vL 100vR 102

Synergy

Pitch Arsenal

Click a pitch to collapse or expand details

4-Seam Fastball

28.4%|Pitching+100

PLoc+

104-> 2027

Velocity

94.2mph

Spin

2241rpm

CSW%

24.8%

iVB / iHB

13.2" / 6.4"

Stuff+

DLoc+

Pitching+

vs L

82▼

114▲

vs R

89▼

114▲

101

Grade drivers

League-average 4-Seam Fastball · 100 → 85.0

Carry along arm slot

−5.5

Break across arm slot

−2.9

Velocity

−1.2

Horizontal geometry

−1.0

Release height

−0.9

Extension

−0.4

Everything else

−3.1

Sinker

21.7%|Pitching+103

PLoc+

101-> 2027

Velocity

93.7mph

Spin

2212rpm

CSW%

20.3%

iVB / iHB

5" / 14.8"

Stuff+

DLoc+

Pitching+

vs L

92▼

100

vs R

107▲

102

107▲

Grade drivers

League-average Sinker · 100 → 95.8

Carry along arm slot

−5.8

Break across arm slot

+4.4

Seam-shifted wake: amount

+3.6

Seam-shifted wake: direction

+1.7

Horizontal geometry

−1.5

Velocity

−1.2

Everything else

−5.4

Slider

16%|Pitching+101

PLoc+

104-> 2027

Velocity

85.6mph

Spin

2518rpm

CSW%

35.1%

iVB / iHB

-0.4" / -3.2"

Stuff+

DLoc+

Pitching+

vs L

88▼

104

101

vs R

101

Grade drivers

League-average Slider · 100 → 90.2

Horizontal geometry

−3.4

Velocity

−3.1

Velo gap vs fastball

+2.0

Spin rate

+1.5

Break across arm slot

−1.5

Seam-shifted wake: amount

−1.5

Everything else

−3.8

Cutter

12.4%|Pitching+105▲

PLoc+

102-> 2027

Velocity

90.2mph

Spin

2424rpm

CSW%

27.9%

iVB / iHB

6.3" / -1.9"

Stuff+

DLoc+

Pitching+

vs L

94▼

108▲

103

vs R

102

106▲

108▲

Grade drivers

League-average Cutter · 100 → 97.5

Break across arm slot

−4.3

Carry along arm slot

+2.8

Vertical approach angle

−2.2

Velocity

+1.4

Seam-shifted wake: direction

+1.2

Extension

−0.9

Everything else

−0.5

Changeup

12.1%|Pitching+106▲

PLoc+

108▲-> 2027

Velocity

87.1mph

Spin

1485rpm

CSW%

17.8%

iVB / iHB

2.6" / 11.9"

Stuff+

DLoc+

Pitching+

vs L

89▼

113▲

104

vs R

94▼

110▲

106▲

Grade drivers

League-average Changeup · 100 → 90.2

Horizontal geometry

−2.8

Vertical break gap vs fastball

+1.7

Break across arm slot

−1.3

Seam-shifted wake: amount

+1.1

Velocity

−1.0

Extension

−1.0

Everything else

−6.5

Sweeper

9.3%|Pitching+90▼

PLoc+

105▲-> 2027

Velocity

79.9mph

Spin

2571rpm

CSW%

28.2%

iVB / iHB

-5.4" / -14.7"

Stuff+

DLoc+

Pitching+

vs L

90▼

88▼

vs R

87▼

85▼

84▼

Grade drivers

League-average Sweeper · 100 → 82.6

Velocity

−5.1

Break across arm slot

−4.5

Horizontal geometry

−3.4

Vertical approach angle

−1.7

Carry along arm slot

−1.4

Seam-shifted wake: amount

−1.1

Everything else

−0.2

xRV (Expected Run Value): Expected runs per 100 pitches using xwOBA on batted balls (BABIP-neutral). Negative = good (runs prevented), Positive = bad (runs allowed).

Similar Pitchers

Last 30 games in 2026

Stephen Kolek

RHP

Team: Kansas City RoyalsThrows: RHeight: 6'3"Weight: 210 lbDOB: Apr 18, 1997Born: Houston, TX, USAActive

Compare

Games

4.50

ERA

9.8%

K-BB%

94.2 mph

FB Velo

25.3%

CSW%

Stuff+

-9 vs MLB 100

vL 87▼vR 96

DLoc+

108

+8 vs MLB 100

vL 109▲vR 108▲

Stockyard PLoc+

104

+4 vs MLB 100

2026 Stockyard PLoc+ -> 2027

Pitching+

-4 vs MLB 100

vL 100vR 102

Synergy

Pitch Arsenal

Click a pitch to collapse or expand details

4-Seam Fastball

28.4%|Pitching+100

PLoc+

104-> 2027

Velocity

94.2mph

Spin

2241rpm

CSW%

24.8%

iVB / iHB

13.2" / 6.4"

Stuff+

DLoc+

Pitching+

vs L

82▼

114▲

vs R

89▼

114▲

101

Grade drivers

League-average 4-Seam Fastball · 100 → 85.0

Carry along arm slot

−5.5

Break across arm slot

−2.9

Velocity

−1.2

Horizontal geometry

−1.0

Release height

−0.9

Extension

−0.4

Everything else

−3.1

Sinker

21.7%|Pitching+103

PLoc+

101-> 2027

Velocity

93.7mph

Spin

2212rpm

CSW%

20.3%

iVB / iHB

5" / 14.8"

Stuff+

DLoc+

Pitching+

vs L

92▼

100

vs R

107▲

102

107▲

Grade drivers

League-average Sinker · 100 → 95.8

Carry along arm slot

−5.8

Break across arm slot

+4.4

Seam-shifted wake: amount

+3.6

Seam-shifted wake: direction

+1.7

Horizontal geometry

−1.5

Velocity

−1.2

Everything else

−5.4

Slider

16%|Pitching+101

PLoc+

104-> 2027

Velocity

85.6mph

Spin

2518rpm

CSW%

35.1%

iVB / iHB

-0.4" / -3.2"

Stuff+

DLoc+

Pitching+

vs L

88▼

104

101

vs R

101

Grade drivers

League-average Slider · 100 → 90.2

Horizontal geometry

−3.4

Velocity

−3.1

Velo gap vs fastball

+2.0

Spin rate

+1.5

Break across arm slot

−1.5

Seam-shifted wake: amount

−1.5

Everything else

−3.8

Cutter

12.4%|Pitching+105▲

PLoc+

102-> 2027

Velocity

90.2mph

Spin

2424rpm

CSW%

27.9%

iVB / iHB

6.3" / -1.9"

Stuff+

DLoc+

Pitching+

vs L

94▼

108▲

103

vs R

102

106▲

108▲

Grade drivers

League-average Cutter · 100 → 97.5

Break across arm slot

−4.3

Carry along arm slot

+2.8

Vertical approach angle

−2.2

Velocity

+1.4

Seam-shifted wake: direction

+1.2

Extension

−0.9

Everything else

−0.5

Changeup

12.1%|Pitching+106▲

PLoc+

108▲-> 2027

Velocity

87.1mph

Spin

1485rpm

CSW%

17.8%

iVB / iHB

2.6" / 11.9"

Stuff+

DLoc+

Pitching+

vs L

89▼

113▲

104

vs R

94▼

110▲

106▲

Grade drivers

League-average Changeup · 100 → 90.2

Horizontal geometry

−2.8

Vertical break gap vs fastball

+1.7

Break across arm slot

−1.3

Seam-shifted wake: amount

+1.1

Velocity

−1.0

Extension

−1.0

Everything else

−6.5

Sweeper

9.3%|Pitching+90▼

PLoc+

105▲-> 2027

Velocity

79.9mph

Spin

2571rpm

CSW%

28.2%

iVB / iHB

-5.4" / -14.7"

Stuff+

DLoc+

Pitching+

vs L

90▼

88▼

vs R

87▼

85▼

84▼

Grade drivers

League-average Sweeper · 100 → 82.6

Velocity

−5.1

Break across arm slot

−4.5

Horizontal geometry

−3.4

Vertical approach angle

−1.7

Carry along arm slot

−1.4

Seam-shifted wake: amount

−1.1

Everything else

−0.2

xRV (Expected Run Value): Expected runs per 100 pitches using xwOBA on batted balls (BABIP-neutral). Negative = good (runs prevented), Positive = bad (runs allowed).

Similar Pitchers

Last 30 games in 2026

Stephen Kolek

Pitch Arsenal

4-Seam Fastball

Sinker

Slider

Cutter

Changeup

Sweeper

Similar Pitchers

Game Log

Stephen Kolek

Pitch Arsenal

4-Seam Fastball

Sinker

Slider

Cutter

Changeup

Sweeper

Similar Pitchers

Game Log