Mithrandir Metrics
Player Kansas City Royals Refreshed Jul 19 06:00 AM ET
Player profile / Kansas City Royals

Stephen Kolek

P · Bats/Throws R/R · 6' 3", 210 lb · Age 29

Cards
7
Modules
1
Live Δ
yes
Club Kansas City Royals Position P Roster Injured 15-Day Status IL-15
Traditional line

Season by season

3D Pitch Lab Projections
WLERAGGSSVIPSOWHIP
2024305.21420046.2391.52
2025573.5119190112.2771.14
2026434.501010054.0341.24
3 Seasons12104.1371290213.11501.25
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.

2026-07-19
52
Pitching
percentile
Pitching9 metrics
49
Arsenal6 metrics
67
Rolling projection

Preseason / current pace / Bayesian update

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

2026-07-19
ERA preseason4.07
ERA current pace4.50
ERA rolling p504.28
Observed weight48%
ERA
3.17 3.70 4.28 4.86 5.38
FIP
3.63 3.94 4.29 4.64 4.96
K%
13.5% 14.8% 16.3% 17.7% 19.0%
BB%
4.5% 5.2% 5.9% 6.7% 7.3%
Live percentile strip

Current traits vs projection tick

100th = best in MLB.

2026-07-19
Pitching · percentile strip
WHIP1.26
61
ERA4.50
37
BB%5.3%
94
K%15.1%
7
xwOBA allowed0.303
62 +43 vs proj
Barrel allowed6.9%
63
Fastball velo94.0
43
Hard-hit allowed37.4%
61
Whiff%18.1%
12
Mithrandir+

Stuff+ and arsenal context

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

2026-07-19
Changeup Stuff+104
60
Cutter Stuff+105
77
Fastball Stuff+105
75
Mithrandir Stuff+105
76
Sinker Stuff+107
87
Slider Stuff+98
26
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 Kolek, Stephen · Live snapshot series; true 50/100 PA windows require PA-level logs LG AVG 0.314 0.303 2026-07-08: 0.3032026-07-09: 0.3032026-07-10: 0.3032026-07-11: 0.3032026-07-12: 0.3032026-07-13: 0.3032026-07-14: 0.3032026-07-15: 0.3032026-07-16: 0.3032026-07-17: 0.3032026-07-18: 0.3032026-07-19: 0.303 2026-07-08 2026-07-19 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.

6Pitches 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 Kolek, Stephen · Aggregate zone metrics; not pitch-by-pitch locations Edge: 38%38%Zone: 50%50%Whiff: 18%18%Called strike: 16%16%First pitch strike: 47%47%Hard hit allowed: 37%37% 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 Kolek, Stephen · 2026 arsenal snapshot 4-Seam Fastball: 28.4%Sinker: 21.7%Slider: 16.2%Cutter: 12.2%Changeup: 12.1%Sweeper: 9.3% FF28% · 94 mphprimary pitch FF 28%SI 22%SL 16%FC 12%CH 12%ST 9% MITHRANDIR · CHARTS
Mithrandir Metrics PITCH MOVEMENT Parameterized Mithrandir chart rendered as SVG for templates and exports. Pitch Arsenal Kolek, Stephen · 2026 arsenal snapshot 15″30″45″60″ 4-Seam Fastball: 28% usage, 3″ horizontal break, 17″ drop, 94.2 mphFF94 mphSinker: 22% usage, 6″ horizontal break, 26″ drop, 93.7 mphSI94 mphSlider: 16% usage, 1″ horizontal break, 38″ drop, 85.6 mphSL86 mphCutter: 12% usage, 1″ horizontal break, 27″ drop, 90.2 mphFC90 mphChangeup: 12% usage, 11″ horizontal break, 34″ drop, 87.1 mphCH87 mphSweeper: 9% usage, 2″ horizontal break, 48″ drop, 79.9 mphST80 mph less drop ↑ more drop ↓ · horizontal break ↔ · dot size = usage · break incl. gravity MITHRANDIR · CHARTS
PitchUsagePitchesStuff+Status
FB 28.6% 105 105 limited sample
SI 22.1% 81 107 limited sample
SL 19.6% 72 98 limited sample
CH 15.8% 58 104 limited sample
FC 13.9% 51 105 limited sample
Method note

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

Reference layer

Current snapshot

Age29
Height6' 3"
Weight210 lb
Debut2024-03-21
Live layer

Delta / regression

ERA Δ+0.06
K% Δ-0.020

positive regression

Regression watch

Unlucky so far. Better days ahead.

1.2σ gap
wOBA-against (actual)0.343
xwOBA-against (deserved)0.303

Kolek’s wOBA-against sits at 0.343, but the quality of contact underneath says it should be 0.303 — a gap of 0.039, 1.2 standard deviations from the MLB norm over 53 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
Pitching72026-07-02Stuff and strike quality carried the outing
Projection links / recent games

Available detail

Pitcher Projections 202617.1% K | 4.44 ERAProjection