George Kirby

SPQualified

Seattle Mariners · AL · Age 28 · Bats R / Throws R · 116.0 IP · 477 BF

— NeutralHOLDRank 486 of 617 pitchers by opportunity score

Opportunity Score

+0.3 last 7 days

HOLDProduction matches the underlying process.

Most likely driver: arm slot raised — pitch-design change or new mechanics (45% confidence).Mechanical flag: arm angle +4.1°.

W-L

8-8

116.0

104

ERA

3.57

WHIP

1.28

Edge breakdown

Expected

What the batted-ball quality deserves

xERA3.75

xwOBA.300

xBA.256

xSLG.388

xBABIP.281

Actual

What the scoreboard says

ERA3.57

wOBA.319

BA.276

SLG.412

BABIP.281

Difference

Actual − expected · percentile of the gap

ERA vs xERA−0.1846

wOBA against vs xwOBA+.01972

BA against vs xBA+.02075

SLG against vs xSLG+.02463

BABIP against vs xBABIP+.00050

Arsenal & pitch shapes

2026 usage, velocity, and movement per pitch · dashed ring = league average for that pitch type · movement in inches, pitcher's perspective

Pitch	Usage	Velo	vs 2025	Velo pctl	Spin	IVB	HB
Sweeper	29.9%(+1.7)	87.2lg 82.5	+0.1	9534	2372	-3.3"lg 0.9	11.5"lg 13.7
4-Seam Fastball	29.4%(+0.6)	96.6lg 94.5	+0.5	8175	2256	13.4"lg 15.4	9.1"lg 7.8
Sinker	20.9%(−5.9)	96.9lg 94.0	+0.6	9008	2307	8.1"lg 8.4	16.5"lg 15.0
Curveball	9.6%(−1.7)	83.9lg 80.3	−0.4	8481	2372	-13.5"lg -10.3	9.5"lg 8.8
Changeup	7.1%(+5.0)	88.8lg 86.6	+1.0	7537	1597	4.9"lg 4.1	14.6"lg 14.0
CutterNEW	3.0%	93.1lg 89.5	—	9422	2352	—lg 7.9	—lg 2.4

IVB = induced vertical break (rise vs gravity-only). HB = horizontal break. Velo percentile is against all pitchers throwing the same pitch type. Sources: Savant pitch arsenals & movement leaderboards.

Mechanics Watch

2026 in gold · 2025 dashed · thin ticks = league average

Arm Angle +4.1°

Arm slot

36 pctl · +4.1° vs prior

What this can't see: Joint kinetics, hip-shoulder separation, and kinematic sequencing (Hawkeye/KinaTrax, team-internal — never estimated here). Stance angle and foot separation (Savant visuals only, no export). Release extension (column exported empty; needs pitch-level ingest).

Metric	Family	Actual	Expected	Diff	Percentile	Edge
Whiff% Whiff% vs baseline	Contact	22.2	26.7	−4.5	12	77
Horiz. Break Horizontal break vs baseline	Movement	9.1	10.1	−1.0	14	71
FB Velo Fastball velo vs baseline	Velocity	96.6	96.1	+0.5	83	66
K% K% vs baseline	Contact	21.8	26.1	−4.3	18	64
xBA BA against vs xBA	Expected vs Actual	.276	.256	+.020	75	51
Hard-Hit% Hard-Hit% against vs league	Quality of Contact	42.2	38.8	+3.4	28	44
xwOBA wOBA against vs xwOBA	Expected vs Actual	.319	.300	+.019	72	44
BB% BB% vs baseline	Discipline	5.2	5.5	−0.3	71	41
Spin Rate Spin rate vs baseline	Spin	2256	2283	−27	31	39
Barrel% Barrel% against vs league	Quality of Contact	6.9	7.8	−0.9	64	27
xSLG SLG against vs xSLG	Expected vs Actual	.412	.388	+.024	63	26
IVB Induced vertical break vs baseline	Movement	13.4	13.4	±0.0	55	10
xERA ERA vs xERA	Expected vs Actual	3.57	3.75	−0.18	46	8
xBABIP BABIP against vs xBABIP	Expected vs Actual	.281	.281	+.000	50	0

Recent games

Date	Opponent	Result	Line	Statcast
Jul 20	@ TB	W 7-0	5.2 IP, 3 ER, 5 K, 1 BB	Avg FB 96.8 mph
Jul 14	vs COL	W 9-2	6.0 IP, 5 ER, 5 K, 2 BB	Avg FB 97.3 mph
Jul 10	vs STL	L 0-4	6.1 IP, 3 ER, 6 K, 1 BB	Avg FB 97.2 mph
Jul 5	vs OAK	L 0-9	6.1 IP, 3 ER, 5 K, 2 BB	Avg FB 97.1 mph
Jun 29	vs KC	W 3-1	6.2 IP, 3 ER, 5 K, 2 BB	Avg FB 96.8 mph
Jun 25	vs PIT	L 2-9	6.2 IP, 3 ER, 7 K, 1 BB	Avg FB 97.4 mph
Jun 20	@ TB	W 9-7	5.0 IP, 3 ER, 6 K, 1 BB	Avg FB 96.1 mph
Jun 15	@ MIA	L 0-1	4.0 IP, 4 ER, 3 K, 1 BB	Avg FB 96.8 mph
Jun 9	vs WSH	W 3-0	4.1 IP, 2 ER, 4 K, 0 BB	Avg FB 96.4 mph
Jun 3	vs WSH	L 3-4	7.0 IP, 3 ER, 6 K, 1 BB	Avg FB 97.0 mph

Percentile rankings

xERA

xwOBA Against

BB%

Whiff%

FB Velocity

Hard-Hit% Against

Spin Rate

30-day rolling trends

Rolling ERA vs xERA

ERAxERA

Rolling Hard-Hit% Against

Rolling FB Velocity

Rolling Stuff Index

Rolling Whiff%

Pitch

Usage

Velo

vs 2025

Velo pctl

Spin

IVB

Sweeper

29.9%(+1.7)

87.2lg 82.5

+0.1

9534

2372

-3.3"lg 0.9

11.5"lg 13.7

4-Seam Fastball

29.4%(+0.6)

96.6lg 94.5

+0.5

8175

2256

13.4"lg 15.4

9.1"lg 7.8

Sinker

20.9%(−5.9)

96.9lg 94.0

+0.6

9008

2307

8.1"lg 8.4

16.5"lg 15.0

Curveball

9.6%(−1.7)

83.9lg 80.3

−0.4

8481

2372

-13.5"lg -10.3

9.5"lg 8.8

Changeup

7.1%(+5.0)

88.8lg 86.6

+1.0

7537

1597

4.9"lg 4.1

14.6"lg 14.0

CutterNEW

3.0%

93.1lg 89.5

—

9422

2352

—lg 7.9

—lg 2.4

Metric

Family

Actual

Expected

Diff

Percentile

Edge

Whiff%

Whiff% vs baseline

Contact

22.2

26.7

−4.5

Horiz. Break

Horizontal break vs baseline

Movement

9.1

10.1

−1.0

FB Velo

Fastball velo vs baseline

Velocity

96.6

96.1

+0.5

K% vs baseline

Contact

21.8

26.1

−4.3

xBA

BA against vs xBA

Expected vs Actual

.276

.256

+.020

Hard-Hit%

Hard-Hit% against vs league

Quality of Contact

42.2

38.8

+3.4

xwOBA

wOBA against vs xwOBA

Expected vs Actual

.319

.300

+.019

BB%

BB% vs baseline

Discipline

5.2

5.5

−0.3

Spin Rate

Spin rate vs baseline

Spin

2256

2283

−27

Barrel%

Barrel% against vs league

Quality of Contact

6.9

7.8

−0.9

xSLG

SLG against vs xSLG

Expected vs Actual

.412

.388

+.024

IVB

Induced vertical break vs baseline

Movement

13.4

±0.0

xERA

ERA vs xERA

Expected vs Actual

3.57

3.75

−0.18

xBABIP

BABIP against vs xBABIP

Expected vs Actual

.281

+.000

Date

Opponent

Result

Line

Jul 20

@ TB

W 7-0

5.2 IP, 3 ER, 5 K, 1 BB

Jul 14

vs COL

W 9-2

6.0 IP, 5 ER, 5 K, 2 BB

Jul 10

vs STL

L 0-4

6.1 IP, 3 ER, 6 K, 1 BB

Jul 5

vs OAK

L 0-9

6.1 IP, 3 ER, 5 K, 2 BB

Jun 29

vs KC

W 3-1

6.2 IP, 3 ER, 5 K, 2 BB

Jun 25

vs PIT

L 2-9

6.2 IP, 3 ER, 7 K, 1 BB

Jun 20

@ TB

W 9-7

5.0 IP, 3 ER, 6 K, 1 BB

Jun 15

@ MIA

L 0-1

4.0 IP, 4 ER, 3 K, 1 BB

Jun 9

vs WSH

W 3-0

4.1 IP, 2 ER, 4 K, 0 BB

Jun 3

vs WSH

L 3-4

7.0 IP, 3 ER, 6 K, 1 BB