Mithrandir Metrics
Player Houston Astros Refreshed Jun 1 06:00 AM ET
Player profile / Houston Astros

Spencer Arrighetti

P profile with live context, projection links, and Mithrandir card history when available.

Cards
6
Modules
1
Live Δ
yes
Club Houston Astros Position P Roster Active Status Healthy / active roster
Rolling projection

Preseason / current pace / Bayesian update

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

2026-06-01
ERA preseason4.12
ERA current pace1.32
ERA rolling p502.85
Observed weight45%
ERA
1.57 2.18 2.85 3.53 4.14
FIP
2.88 3.35 3.87 4.39 4.85
K%
20.0% 21.6% 23.5% 25.3% 27.0%
BB%
8.9% 10.0% 11.2% 12.4% 13.4%
Live percentile strip

Current traits vs projection tick

100th = best in MLB.

2026-06-01
Pitching · percentile strip
BB%13.1%
10 -25 vs proj
Barrel allowed5.8%
74 +34 vs proj
Fastball velo92.5
22
Hard-hit allowed29.8%
94
K%21.6%
46
Whiff%22.5%
46 -16 vs proj
xwOBA allowed0.339
27
Mithrandir+

Stuff+ and arsenal context

Stuff+ appears when the current pitch-event scoring artifact includes this pitcher; missing coverage is shown explicitly.

2026-06-01
Mithrandir Stuff+101
42
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 Arrighetti, Spencer · Live snapshot series; true 50/100 PA windows require PA-level logs LG AVG 0.314 2026-05-17: 0.3502026-05-19: 0.3502026-05-21: 0.3502026-05-23: 0.3452026-05-24: 0.3432026-05-25: 0.3432026-05-26: 0.3432026-05-28: 0.3432026-05-29: 0.3432026-05-30: 0.3392026-05-31: 0.3392026-06-01: 0.339 2026-05-17 2026-06-01 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 33%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 Arrighetti, Spencer · Aggregate zone metrics; not pitch-by-pitch locations Edge: 36%36%Zone: 46%46%Whiff: 23%23%Called strike: 18%18%First pitch strike: 45%45%Hard hit allowed: 30%30% 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.

2026
Mithrandir Metrics PITCH ARSENAL DONUT Parameterized Mithrandir chart rendered as SVG for templates and exports. Pitch Arsenal Arrighetti, Spencer · 2026 arsenal snapshot Curveball: 33.4%4-Seam Fastball: 30.0%Sweeper: 13.5%Sinker: 10.4%Changeup: 7.4%Cutter: 5.3% MIX CU 33%FF 30%ST 13%SI 10%CH 7%FC 5% MITHRANDIR · CHARTS
Mithrandir Metrics PITCH MOVEMENT Parameterized Mithrandir chart rendered as SVG for templates and exports. Pitch Arsenal Arrighetti, Spencer · 2026 arsenal snapshot CU: HB 0.6, IVB 4.5CUFF: HB -0.3, IVB 1.5FFST: HB -0.3, IVB 3.5STSI: HB 0.7, IVB 2.0SICH: HB -1.1, IVB 3.0CHFC: HB 0.0, IVB 2.1FC horizontal break IVB MITHRANDIR · CHARTS
PitchUsagePitchesStuff+Status
CB 32.0% 212 100 qualified
FB 30.2% 200 104 qualified
SL 14.5% 96 101 limited sample
SI 9.8% 65 103 limited sample
CH 7.7% 51 93 limited sample
FC 5.7% 38 110 limited sample
Method note

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

Reference layer

Current snapshot

Age26
Height6' 2"
Weight186 lb
Debut2024-04-10
Live layer

Delta / regression

ERA Δ-2.97
K% Δ-0.025

negative regression

Mithrandir coverage

Module shelf

ModuleCardsLatestSignal
Pitching62026-05-22Curveball played up through FF/ST tunnel quality
Projection links / recent games

Available detail

Pitcher Projections 202624.1% K | 4.29 ERAProjection
2026-04-20 @ CLE2 ER / 3 K5.0 IP
2026-04-15 vs COL1 ER / 10 K6.0 IP