Mithrandir Metrics
Player Seattle Mariners Refreshed Sep 26 06:00 AM ET
Player profile / Seattle Mariners

George Kirby

P · Bats/Throws R/R · 6' 4", 215 lb · Age 28

Cards
33
Modules
1
Live Δ
yes
Club Seattle Mariners Position P Roster Current MLB team Status Healthy / active roster
Traditional line

Season by season

3D Pitch Lab Projections
WLERAGGSSVIPSOWHIP
202414113.5333330191.01791.07
20251084.2123230126.01371.19
20269114.3330300174.21481.40
5 Seasons54453.741421420812.17691.17
At a glance

Season percentile report

The headline weighs outcome stats (xwOBA, barrels); each bar averages its full strip group below. 100 = best in MLB.

2026-09-26
49
Pitching
percentile
Pitching9 metrics
51
Arsenal7 metrics
74
Rolling projection

Preseason / current pace / Bayesian update

Rolling bands shrink current-season signal toward the preseason prior until the sample earns more weight.

2026-09-26
ERA preseason3.59
ERA current pace4.24
ERA rolling p504.09
Observed weight77%
ERA
2.95 3.49 4.09 4.69 5.23
FIP
3.24 3.55 3.88 4.22 4.52
K%
18.6% 19.6% 20.7% 21.7% 22.7%
BB%
5.1% 5.6% 6.1% 6.6% 7.0%
Live percentile strip

Current traits vs projection tick

100th = best in MLB.

2026-09-26
Pitching · percentile strip
WHIP1.43
31
ERA4.24
45
BB%6.3%
87
K%19.8%
34 -33 vs proj
xwOBA allowed0.315
47
Barrel allowed6.6%
63 +28 vs proj
Fastball velo96.8
85
Hard-hit allowed41.2%
31
Whiff%21.3%
39
Mithrandir+

Stuff+ and arsenal context

How nasty this pitcher's stuff grades in our pitch-level model. Missing coverage is shown explicitly.

2026-09-26
Fastball Stuff+106
76
Mithrandir Stuff+107
92
Sinker Stuff+109
94
Slider Stuff+108
92
Changeup Stuff+103
61
Curveball Stuff+104
71
Cutter Stuff+99
32
Rolling form chart

xwOBA allowed snapshot line

Live snapshot series; true 50/100 PA windows require PA-level logs

12 snapshots
Mithrandir Metrics ROLLING XWOBA LINE Parameterized Mithrandir chart rendered as SVG for templates and exports. season=2026 Rolling xwOBA allowed Kirby, George · Live snapshot series; true 50/100 PA windows require PA-level logs LG AVG 0.313 0.315 2026-09-12: 0.3132026-09-13: 0.3132026-09-14: 0.3132026-09-18: 0.3152026-09-19: 0.3152026-09-20: 0.3152026-09-21: 0.3152026-09-22: 0.3152026-09-23: 0.3152026-09-24: 0.3152026-09-25: 0.3152026-09-26: 0.315 2026-09-12 2026-09-26 xwOBA allowed MITHRANDIR · CHARTS
Optimization map

Arsenal optimization map

Pitch-shape context from this pitcher’s current arsenal snapshot. Hover a pitch to inspect usage, movement, and bat-missing context.

7Pitches 2026Season 28%Top usage
ride armside gloveside +Arsenal gap +Shape contrast
Zone profile

Aggregate zone heatmap

Aggregate zone metrics from seasonal Statcast leaderboards.

Mithrandir Metrics ZONE HEATMAP Parameterized Mithrandir chart rendered as SVG for templates and exports. season=2026 Pitch Zone Profile Kirby, George · Aggregate zone metrics; not pitch-by-pitch locations Edge: 38%38%Zone: 49%49%Whiff: 21%21%Called strike: 15%15%First pitch strike: 52%52%Hard hit allowed: 41%41% Dashed border = aggregate mixed-batter zone proxy MITHRANDIR · CHARTS
Pitch arsenal

Usage mix, movement map, and Stuff+ composition

2026 pitch-level arsenal aggregates; current season takes over after 100 tracked pitches across at least 2 pitch types. Descriptive pitch-type Stuff+ composition. Not a promoted predictive metric.

Watch the pitches in 3D →

2026
Mithrandir Metrics PITCH ARSENAL DONUT Parameterized Mithrandir chart rendered as SVG for templates and exports. Pitch Arsenal Kirby, George · 2026 arsenal snapshot 4-Seam Fastball: 28.3%Sweeper: 28.2%Sinker: 20.9%Knuckle Curve: 10.1%Changeup: 5.9%Cutter: 4.1% FF28% · 97 mphprimary pitch FF 28%ST 28%SI 21%KC 10%CH 6%FC 4% MITHRANDIR · CHARTS
Mithrandir Metrics PITCH MOVEMENT Parameterized Mithrandir chart rendered as SVG for templates and exports. Pitch Arsenal Kirby, George · 2026 arsenal snapshot 15″30″45″60″ 4-Seam Fastball: 28% usage, 2″ horizontal break, 16″ drop, 96.7 mphFF97 mphSweeper: 28% usage, 2″ horizontal break, 39″ drop, 87.5 mphST87 mphSinker: 21% usage, 9″ horizontal break, 21″ drop, 96.9 mphSI97 mphKnuckle Curve: 10% usage, 6″ horizontal break, 52″ drop, 84.1 mphKC84 mphChangeup: 6% usage, 7″ horizontal break, 30″ drop, 88.7 mphCH89 mphCutter: 4% usage, 0″ horizontal break, 23″ drop, 92.9 mphFC93 mphSplit-Finger: 2% usage, 6″ horizontal break, 35″ drop, 87.2 mphFS87 mph less drop ↑ more drop ↓ · horizontal break ↔ · dot size = usage · break incl. gravity MITHRANDIR · CHARTS
PitchUsagePitchesStuff+Status
FB 29.8% 515 106 qualified
SL 27.1% 469 108 qualified
SI 21.4% 370 109 qualified
CB 10.4% 179 104 limited sample
CH 6.6% 114 103 limited sample
FC 4.7% 81 99 limited sample
Method note

Renamed from the attempted Kirby Index after audit; true Kirby requires release-angle trajectory data.

Reference layer

Current snapshot

Age28
Height6' 4"
Weight215 lb
Debut2022-05-08
Live layer

Delta / regression

ERA Δ+0.80
K% Δ-0.045

positive regression

Regression watch

Unlucky so far. Better days ahead.

2.2σ gap
wOBA-against (actual)0.368
xwOBA-against (deserved)0.315

Kirby’s wOBA-against sits at 0.368, but the quality of contact underneath says it should be 0.315 — a gap of 0.053, 2.2 standard deviations from the MLB norm over 181 IP. The results have been worse than the process deserves; as the sample grows, expect the numbers to climb back toward the underlying level.

Mithrandir coverage

Module shelf

ModuleCardsLatestSignal
Pitching332026-09-23Four-Seam Fastball played up through FF/ST tunnel quality
Projection links / recent games

Available detail

Pitcher Projections 202624.3% K | 3.44 ERAProjection
2026-04-13 vs HOU2 ER / 6 K7.2 IP
2026-04-07 @ TEX3 ER / 4 K8.0 IP
2026-04-01 vs NYY4 ER / 6 K6.0 IP
2026-03-27 vs CLE1 ER / 6 K6.0 IP