Players · M · Pitcher · 2026

Seth Martinez

Age: 32
B/T: R/R
Height: 6' 2"
Weight: 193 lb
Number: #51

Born: August 29, 1994 in Peoria, AZ, United States
MLB debut: September 20, 2021
Drafted: 2016, round 17
College: Arizona State
High school: Sunrise Mountain

dbWAR: .5
IP: 1.0
ERA: 9.00
FIP: 4.10
K/9: 9.0
FIP−: 98

Seth Martinez is a relief pitcher for the Boston Red Sox. In 2026 he struck out 1 batter over 1.0 inning across 1 appearance, going 0-0. His ERA of 9.00 is 115.4% higher than the league average of 4.18. Stripping out defence, his 4.10 FIP suggests he pitched better than his ERA shows. He missed bats on 36.4% of swings (18.2% of every pitch he threw), walked 0.0% of the batters he faced and struck out 16.7%. His 0.0 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.

FIP4.10

K/99.0

WHIP2.00

WAR.0

WAR by season

Pitching

Standard and advanced, by season.


2026	BOS	1	1.0	0	0	0	2	1	1	0	9.00	4.10	2.00	9.0	0.0	215	98	0.0
2025	MIA	6	6.2	0	0	0	4	4	4	3	5.40	7.19	1.05	5.4	4.0	130	173	-0.2
2024	HOU	44	52.2	3	2	1	49	21	36	18	3.59	4.78	1.27	6.2	3.1	88	117	-0.1
2023	HOU	35	43.0	2	3	1	45	25	45	19	5.23	4.42	1.49	9.4	4.0	121	102	0.2
2022	HOU	29	38.2	1	1	0	26	9	38	14	2.09	3.32	1.03	8.8	3.3	53	84	0.5
2021	HOU	3	3.0	0	0	0	5	5	3	3	15.00	4.17	2.67	9.0	9.0	352	98	0.0

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	2	1	0	0	0	1	.000	.500	.000	.374	50.0%
vs RHB	4	4	2	0	0	0	.500	.500	.750	.537	0.0%

Pitch sequencing

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

ShowBatter

SweeperSinker

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Pitch arsenal

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

Season

Head to head

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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.