George Kirby

Active

Seattle Mariners · Pitcher

Age 286' 4" · 215 lbsThrows Right

#67 Preseason#69 Dynasty

FBaseball Overview

This 28-year-old right-hander continues to anchor Seattle's rotation as a reliable mid-tier starter who produced an All-Star season in 2023 and maintains consistent strikeout production despite modest win totals. His 2026 campaign shows slight regression in ERA and WHIP compared to 2025, though he still delivers over 90 strikeouts across roughly 100 innings while posting a winning record. Kirby offers fantasy managers steady strikeout value and respectable ERA numbers in deeper leagues, but his win-loss record remains dependent on Seattle's offense and bullpen support. The primary risk is limited upside in wins and saves, making him best suited as a backend starter in standard 12-team leagues rather than a league-winner.

News Updates

Kirby takes loss; Mariners fall to Athletics
Mariners pitcher George Kirby (9-11) took the loss against Oakland, giving up four runs on seven hits across 6.2 innings with five strikeouts. The defeat adds to Seattle's struggles in the stretch run.
Sep 6, 2026
George Kirby rebounds with dominant start
Seattle Mariners pitcher George Kirby earned the win against Philadelphia, allowing just one run on six hits across 7.2 innings with nine strikeouts. Kirby's strong performance improves his season record to 9-10 and demonstrates his capability to deliver quality starts in important games.
Aug 26, 2026

MLB Pitching

Year	Team	G	GS	W	L	ERA	WHIP	K	IP	BB
2022	Seattle Mariners	25	25	8	5	3.39	1.21	133	130.0	22
2023	Seattle Mariners	31	31	13	10	3.35	1.04	172	190.2	19
2024	Seattle Mariners	33	33	14	11	3.53	1.07	179	191.0	23
2025	Seattle Mariners	23	23	10	8	4.21	1.19	137	126.0	29
2026	Seattle Mariners	27	27	9	11	4.18	1.34	133	159.1	37
Career	Totals	139	139	54	45	3.70	1.16	754	797	130

Source: MLB Stats API · Multi-team seasons show combined totals — click to expand

Minor League Pitching

Year	Team	G	GS	W	L	ERA	WHIP	K	IP	BB
2019	Everett AquaSox	9	8	0	0	2.35	1.04	25	23.0	0
2021	2 teams▼	15	15	5	3	2.53	1.08	80	67.2	15
2022	2 teams▼	6	6	2	1	3.04	1.05	34	26.2	6
2025	Tacoma Rainiers	3	3	0	0	7.20	1.70	13	10.0	2
Career	Totals	33	32	7	4	2.97	1.12	152	127.1	23

Source: MLB Stats API · Multi-team seasons show combined totals — click to expand

Game Log2026 MLB

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Advanced Stats2026 season · via Baseball Savant

Click for year to year changes

FB Velo96.7 mph

Avg Spin2259 rpm

Whiff %21.9%

K %19.9%

BB %5.5%

Hard Hit %40.3%

Barrel %6.9%

xERA4.04

xBA Against0.260

xSLG Against0.407

BA Against0.283

SLG Against0.445

GB%44.5%

FB%25.1%

What These Stats Mean

FB Velo — Average fastball velocity. Harder throwers generate more swings and misses, setting up every other pitch in their arsenal. Velocity is the foundation of strikeout upside.

Avg Spin — Average spin rate across all pitches. Higher spin creates more movement and makes pitches harder to square up — elite spinners run better strikeout and batting average against numbers.

Whiff % — Swings-and-misses per swing. The most direct measure of a pitcher's ability to miss bats and the best leading indicator of strikeout rate.

K % — Strikeout rate per batter faced. The core fantasy pitching stat — high K% means reliable strikeout totals that hold up even in shorter starts.

BB % — Walk rate per batter faced. The primary control metric. High BB% tanks ERA and WHIP and keeps baserunners on constantly. Elite starters typically run below 7%.

Hard Hit % — Percentage of batted balls hit 95 mph or harder against. Low hard-hit% means weak contact, protecting both ERA and the defense behind the pitcher.

Barrel % — Percentage of batted balls barreled against. The most direct home run predictor — low barrel% pitchers rarely give up long balls.

xERA — Expected ERA based on contact quality allowed, removing the effect of sequencing, luck, and defense. Better predictor of future ERA than ERA itself.

xBA Against — Expected batting average opponents should hit based on contact quality. A gap between xBA and actual BA indicates unsustainable luck in either direction.

xSLG Against — Expected slugging allowed based on contact quality. High xSLG against predicts future extra-base damage; low xSLG means the pitcher is genuinely suppressing power.

BA Against — Actual batting average opponents are hitting — a key WHIP component. Check xBA to see if the number is sustainable.

SLG Against — Actual slugging allowed. Captures hits, doubles, triples, and home runs — lower means the pitcher is limiting the power damage he gives up.

GB% — Ground ball rate. High GB% pitchers generate double plays, limit home runs, and keep the ball in the park — great for protecting ERA and WHIP ratios.

FB% — Fly ball rate. High FB% pitchers give up more air contact — dangerous when combined with high exit velocity, less so when contact is soft.

Articles featuring George Kirby

Top Waiver Wire Adds: June 28, 2026
June 28, 2026
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Loading player data...

Year

Team

ERA

WHIP

2022

Seattle Mariners

3.39

1.21

133

130.0

2023

Seattle Mariners

3.35

1.04

172

190.2

2024

Seattle Mariners

3.53

1.07

179

191.0

2025

Seattle Mariners

4.21

1.19

137

126.0

2026

Seattle Mariners

4.18

1.34

133

159.1

Career

Totals

139

3.70

1.16

754

797

130

Year

Team

ERA

WHIP

2019

Everett AquaSox

2.35

1.04

23.0

2021

2 teams▼

2.53

1.08

67.2

2022

2 teams▼

3.04

1.05

26.2

2025

Tacoma Rainiers

7.20

1.70

10.0

Career

Totals

2.97

1.12

152

127.1