Mithrandir Metrics
Player Boston Red Sox Refreshed Jun 1 06:00 AM ET
Player profile / Boston Red Sox

Justin Slaten

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

Cards
0
Modules
0
Live Δ
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Club Boston Red Sox 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 preseason3.74
ERA current pace4.15
ERA rolling p503.82
Observed weight19%
ERA
2.12 2.93 3.82 4.71 5.52
FIP
2.86 3.28 3.74 4.21 4.63
K%
17.1% 20.1% 23.5% 26.8% 29.8%
BB%
5.1% 6.5% 8.2% 9.8% 11.2%
Live percentile strip

Current traits vs projection tick

100th = best in MLB.

2026-06-01
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+108
92
Rolling form chart

xwOBA allowed snapshot line

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

0 snapshots
No chart yet

No Live State xwOBA snapshots are available for this player.

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.

5Pitches 2026Season 51%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 Slaten, Justin · Aggregate zone metrics; not pitch-by-pitch locations Edge: 37%37%Zone: 57%57%Whiff: 22%22%Called strike: 17%17%First pitch strike: 55%55%Hard hit allowed: 45%45% 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 Slaten, Justin · 2026 arsenal snapshot Cutter: 51.2%4-Seam Fastball: 28.4%Sweeper: 17.2%Curveball: 2.8%Split-Finger: 0.5% MIX FC 51%FF 28%ST 17%CU 3%FS 0% MITHRANDIR · CHARTS
Mithrandir Metrics PITCH MOVEMENT Parameterized Mithrandir chart rendered as SVG for templates and exports. Pitch Arsenal Slaten, Justin · 2026 arsenal snapshot FC: HB -0.1, IVB 2.0FCFF: HB 0.0, IVB 1.0FFST: HB -0.5, IVB 2.9STCU: HB 0.4, IVB 4.1CUFS: HB -1.1, IVB 2.7FS horizontal break IVB MITHRANDIR · CHARTS
PitchUsagePitchesStuff+Status
FC 51.3% 77 106 limited sample
FB 30.0% 45 110 limited sample
SL 16.0% 24 96 limited sample
CB 2.7% 4 108 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"
Weight222 lb
Debut2024-03-30
Live layer

Delta / regression

No Live State delta is available for this profile yet.

Mithrandir coverage

Module shelf

ModuleCardsLatestSignal
No Mithrandir card history is available for this player yet.
Projection links / recent games

Available detail

Pitcher Projections 202622.2% K | 3.79 ERAProjection
2026-04-04 vs SD0 ER / 1 K1.0 IP
2026-04-03 vs SD0 ER / 1 K1.0 IP
2026-03-26 @ CIN0 ER / 2 K1.0 IP