George Kirby

Active

Seattle Mariners · Pitcher

Age 286' 4" · 215 lbsThrows Right

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.

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	17	17	7	7	3.81	1.32	91	104.0	24
Career	Totals	129	129	52	41	3.62	1.14	712	741.2	117

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 season

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Analytics2026 season · via Baseball Savant

Click for year to year changes

FB Velo96.8 mph

Avg Spin2271 rpm

Whiff %21.4%

K %21.1%

BB %5.6%

Hard Hit %41.6%

Barrel %6.7%

xERA3.72

xBA Against0.256

xSLG Against0.383

BA Against0.279

SLG Against0.410

GB%49.8%

FB%24.8%

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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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

3.81

1.32

104.0

Career

Totals

129

3.62

1.14

712

741.2

117

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