STL · P

Kyle Leahy

Age 29 B/T S/R 6′5″, 225 lb USA MLB debut 2023

40-man

St. Louis’ roster as it stands #1 starter · 109 IP · 1.5 WAR in the role
Trade read Available at a price: STL sits near the seller line (27% playoff odds, within a projected win of 30%); control through 2030.

Keystone Stuff 95 27th pct

2026 fWAR 2.6

Projected 2027 WAR 1.5 at 109 IP · 1.5 in his 2027 role

Pitching · 2026 percentiles

vs. MLB pitchers with 500+ pitches · 2,327 pitches

Keystone Stuff 95

Keystone Location 107

Keystone Pitching 97

Run value (xRV) −0.44

Strikeout % 22.1%

Walk % 6.9%

Whiff % 22.7%

Chase % 27.2%

Fastball velo 94.2

Extension 7.2 ft

140.0 IP3.66 ERA3.59 FIP 43° arm

Arsenal & Pitch Lab

Movement normalized to arm side · Keystone Stuff by pitch

RHP · arm angle 43° · how to read

Pitch	Use	Velo	IVB	HB	Stuff	Loc	Whiff	xRV/100
Four-seam26% use	26%	94.3	14.5	+4.5	94	99	17%	−1.60
Curveball16% use	16%	83.0	−10.8	−8.6	92	96	27%	−0.28
Slider16% use	16%	89.4	3.8	−5.0	96	114	23%	+0.73
Changeup15% use	15%	88.6	1.7	+11.5	93	100	32%	−0.57
Sweeper14% use	14%	84.8	2.1	−16.5	110	103	26%	+0.10
Sinker13% use	13%	94.2	10.6	+13.2	94	115	12%	−0.25

Weak pitch to watch

Changeup grades 93 with below-average expected results; his sweeper grades 110. The best case is against lefties: the sweeper is worth +0.5 runs per 100 pitches more, 0.6 standard errors (105 and 282 pitches), short of the 2 needed. No mix change until it clears.

Weak pitch to watch

Curveball grades 92 with below-average expected results; his sweeper grades 110. The best case is against righties: the sweeper is worth +0.8 runs per 100 pitches more, 0.9 standard errors (211 and 131 pitches), short of the 2 needed. No mix change until it clears.

Weak pitch to watch

Four-seam grades 94 with below-average expected results; his sweeper grades 110. The best case is against lefties: the sweeper is worth +1.0 runs per 100 pitches more, 1.3 standard errors (105 and 401 pitches), short of the 2 needed. No mix change until it clears.

Most similar pitchers

Pitches like Leahy: same hand, shape, slot and mix

Similarity	Player	Stuff	’26 WAR	’27 proj	2027
52	Shane Bieber TOR · ’95	94	0.1	0.4	Free agent
51	Gabriel Hughes COL · ’01	97	1.1	1.3	—
49	Brandon Pfaadt AZ · ’98	96	2.2	2.0	Signed $5.4M
46	Davis Martin CWS · ’97	88	2.6	1.8	Pre-arb
45	Ryan Gusto MIA · ’99	97	1.0	1.1	—

Same-handed pitchers nearest on fastball velocity and shape, arm angle, extension, pitch mix, secondary shapes, Stuff, whiff rate and workload. 2026 regulars only.

Pitch locations · 2026

Where each pitch finishes, by batter side

Four-seam 32%

45% zone

Changeup 23%

31% zone

Curveball 20%

37% zone

Slider 13%

56% zone

Sweeper 8%

49% zone

Sinker 4%

66% zone

Where each pitch finishes, catcher’s view. The bar marks the batter’s side; the box is an average strike zone. Pitches with 40+ thrown to this side.

Contract & projection

Club control (RosterResource) · Keystone projected WAR

2027 1.5 WAR Arbitration $3.7M*

2028 1.3 WAR Arbitration $5.4M*

2029 1.1 WAR Arbitration $7.4M*

2030 0.9 WAR Arbitration $8.4M*

* projected arbitration or minimum salary. Contract Studio →