Mithrandir Metrics
Player Washington Nationals Refreshed Sep 27 06:00 AM ET
Player profile / Washington Nationals

Dj Herz

P · Bats/Throws R/L · 6' 2", 197 lb · Age 25

Cards
1
Modules
1
Live Δ
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Club Washington Nationals Position P Roster Current MLB team Status Healthy / active roster
Traditional line

Season by season

3D Pitch Lab Projections
WLERAGGSSVIPSOWHIP
2024494.161919088.21061.26
20260110.292207.062.00
2 Seasons4104.612121095.21121.32
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.

2026-09-27
33
Pitching
percentile
Arsenal4 metrics
33
Rolling projection

Preseason / current pace / Bayesian update

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

2026-09-27
ERA preseason4.12
ERA current pace9.00
ERA rolling p504.48
Observed weight7%
ERA
3.23 3.82 4.48 5.13 5.73
FIP
2.60 3.14 3.75 4.35 4.89
K%
18.7% 20.8% 23.3% 25.7% 27.8%
BB%
5.7% 6.8% 8.0% 9.2% 10.4%
Live percentile strip

Current traits vs projection tick

100th = best in MLB.

2026-09-27
Mithrandir+

Stuff+ and arsenal context

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

2026-09-27
Changeup Stuff+103
63
Fastball Stuff+98
23
Mithrandir Stuff+98
20
Slider Stuff+99
27
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.

4Pitches 2026Season 48%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 Herz, Dj · Aggregate zone metrics; not pitch-by-pitch locations Edge: 35%35%Zone: 51%51%Whiff: 21%21%Called strike: 16%16%First pitch strike: 37%37%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 Herz, Dj · 2026 arsenal snapshot 4-Seam Fastball: 47.6%Changeup: 31.7%Slider: 17.5%Knuckle Curve: 3.2% FF48% · 93 mphprimary pitch FF 48%CH 32%SL 17%KC 3% MITHRANDIR · CHARTS
Mithrandir Metrics PITCH MOVEMENT Parameterized Mithrandir chart rendered as SVG for templates and exports. Pitch Arsenal Herz, Dj · 2026 arsenal snapshot 12″24″36″48″ 4-Seam Fastball: 48% usage, 12″ horizontal break, 16″ drop, 93.0 mphFF93 mphChangeup: 32% usage, 14″ horizontal break, 34″ drop, 82.8 mphCH83 mphSlider: 17% usage, 1″ horizontal break, 25″ drop, 87.5 mphSL87 mphKnuckle Curve: 3% usage, 0″ horizontal break, 40″ drop, 80.3 mphKC80 mph less drop ↑ more drop ↓ · horizontal break ↔ · dot size = usage · break incl. gravity MITHRANDIR · CHARTS
PitchUsagePitchesStuff+Status
FB 47.6% 30 98 limited sample
CH 31.7% 20 103 limited sample
SL 17.5% 11 99 limited sample
CB 3.2% 2 92 limited sample
Method note

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

Reference layer

Current snapshot

Age25
Height6' 2"
Weight197 lb
Debut2024-06-04
Live layer

Delta / regression

No Live State delta is available for this profile yet.

Mithrandir coverage

Module shelf

ModuleCardsLatestSignal
Pitching12026-09-21Four-Seam Fastball played up through FF/CH tunnel quality
Projection links / recent games

Available detail

Pitcher Projections 202624.1% K | 4.36 ERAProjection