Mithrandir Metrics
Player Pittsburgh Pirates Refreshed Sep 26 06:00 AM ET
Player profile / Pittsburgh Pirates

Kirby Yates

P · Bats/Throws L/R · 5' 10", 205 lb · Age 39

Cards
0
Modules
0
Live Δ
yes
Club Pittsburgh Pirates Position P Roster Current MLB team Status Healthy / active roster
Traditional line

Season by season

3D Pitch Lab Projections
WLERAGGSSVIPSOWHIP
2024721.176103361.2850.83
2025435.23500341.1521.33
2026253.32450340.2481.20
12 Seasons32293.365170101493.16711.14
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
71
Pitching
percentile
Pitching9 metrics
57
Arsenal2 metrics
31
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 preseason4.06
ERA current pace3.40
ERA rolling p503.78
Observed weight42%
ERA
1.94 2.81 3.78 4.75 5.62
FIP
2.32 2.91 3.56 4.21 4.80
K%
24.5% 26.7% 29.2% 31.7% 33.9%
BB%
7.1% 8.5% 9.9% 11.4% 12.7%
Live percentile strip

Current traits vs projection tick

100th = best in MLB.

2026-09-26
Pitching · percentile strip
WHIP1.20
74
ERA3.40
72
BB%9.7%
41
K%28.0%
86
xwOBA allowed0.286
80 +22 vs proj
Barrel allowed5.7%
79 +53 vs proj
Fastball velo90.8
6
Hard-hit allowed45.7%
8
Whiff%25.4%
71
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+99
30
Mithrandir Stuff+100
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 Yates, Kirby · Live snapshot series; true 50/100 PA windows require PA-level logs LG AVG 0.313 0.286 2026-09-12: 0.2872026-09-13: 0.2872026-09-14: 0.2872026-09-18: 0.2872026-09-19: 0.2872026-09-20: 0.2872026-09-21: 0.2872026-09-22: 0.2872026-09-23: 0.2872026-09-24: 0.2862026-09-25: 0.2862026-09-26: 0.286 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.

3Pitches 2026Season 66%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 Yates, Kirby · Aggregate zone metrics; not pitch-by-pitch locations Edge: 38%38%Zone: 45%45%Whiff: 25%25%Called strike: 13%13%First pitch strike: 49%49%Hard hit allowed: 46%46% 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 Yates, Kirby · 2026 arsenal snapshot 4-Seam Fastball: 65.8%Split-Finger: 32.2%Sweeper: 2.0% FF66% · 91 mphprimary pitch FF 66%FS 32%ST 2% MITHRANDIR · CHARTS
Mithrandir Metrics PITCH MOVEMENT Parameterized Mithrandir chart rendered as SVG for templates and exports. Pitch Arsenal Yates, Kirby · 2026 arsenal snapshot 15″30″45″60″ 4-Seam Fastball: 66% usage, 0″ horizontal break, 20″ drop, 90.8 mphFF91 mphSplit-Finger: 32% usage, 1″ horizontal break, 40″ drop, 84.4 mphFS84 mphSweeper: 2% usage, 2″ horizontal break, 51″ drop, 74.9 mphST75 mph less drop ↑ more drop ↓ · horizontal break ↔ · dot size = usage · break incl. gravity MITHRANDIR · CHARTS
PitchUsagePitchesStuff+Status
FB 97.1% 236 99 qualified
SL 2.9% 7 94 limited sample
Method note

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

Reference layer

Current snapshot

Age39
Height5' 10"
Weight205 lb
Debut2014-06-07
Live layer

Delta / regression

ERA Δ-0.63
K% Δ+0.009

positive regression

Regression watch

Unlucky so far. Better days ahead.

0.3σ gap
wOBA-against (actual)0.296
xwOBA-against (deserved)0.286

Yates’s wOBA-against sits at 0.296, but the quality of contact underneath says it should be 0.286 — a gap of 0.011, 0.3 standard deviations from the MLB norm over 41 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
No Mithrandir card history is available for this player yet.
Projection links / recent games

Available detail

Pitcher Projections 202627.1% K | 4.03 ERAProjection
2026-05-20 vs ATH1 ER / 1 K0.2 IP