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

Seth Johnson

P · Bats/Throws R/R · 6' 1", 205 lb · Age 28

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

Season by season

3D Pitch Lab Projections
WLERAGGSSVIPSOWHIP
20240134.711102.104.71
2025114.26100012.2171.18
2026106.00281033.0391.64
3 Seasons226.94392048.0561.67
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
29
Pitching
percentile
Pitching9 metrics
36
Arsenal5 metrics
55
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 preseason3.93
ERA current pace6.19
ERA rolling p504.83
Observed weight40%
ERA
3.12 3.93 4.83 5.73 6.54
FIP
2.74 3.31 3.95 4.59 5.16
K%
19.9% 22.5% 25.3% 28.1% 30.6%
BB%
6.6% 7.9% 9.4% 10.9% 12.2%
Live percentile strip

Current traits vs projection tick

100th = best in MLB.

2026-09-27
Pitching · percentile strip
WHIP1.65
10
ERA6.19
8
BB%12.0%
18 -28 vs proj
K%25.9%
77
xwOBA allowed0.331
30 -42 vs proj
Barrel allowed11.5%
5 -41 vs proj
Fastball velo97.4
91
Hard-hit allowed44.8%
10
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.

2026-09-27
Curveball Stuff+96
2
Fastball Stuff+104
67
Mithrandir Stuff+106
86
Sinker Stuff+98
22
Slider Stuff+111
98
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 Johnson, Seth · Live snapshot series; true 50/100 PA windows require PA-level logs LG AVG 0.313 0.331 2026-09-13: 0.3362026-09-14: 0.3362026-09-18: 0.3212026-09-19: 0.3252026-09-20: 0.3252026-09-21: 0.3252026-09-22: 0.3252026-09-23: 0.3362026-09-24: 0.3362026-09-25: 0.3362026-09-26: 0.3312026-09-27: 0.331 2026-09-13 2026-09-27 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 46%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 Johnson, Seth · Aggregate zone metrics; not pitch-by-pitch locations Edge: 38%38%Zone: 48%48%Whiff: 25%25%Called strike: 17%17%First pitch strike: 41%41%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.

Watch the pitches in 3D →

2026
Mithrandir Metrics PITCH ARSENAL DONUT Parameterized Mithrandir chart rendered as SVG for templates and exports. Pitch Arsenal Johnson, Seth · 2026 arsenal snapshot 4-Seam Fastball: 46.5%Slider: 32.4%Sinker: 9.4%Curveball: 5.4%Sweeper: 4.5%Split-Finger: 1.8% FF46% · 98 mphprimary pitch FF 46%SL 32%SI 9%CU 5%ST 5%FS 2% MITHRANDIR · CHARTS
Mithrandir Metrics PITCH MOVEMENT Parameterized Mithrandir chart rendered as SVG for templates and exports. Pitch Arsenal Johnson, Seth · 2026 arsenal snapshot 12″24″36″48″ 4-Seam Fastball: 46% usage, 0″ horizontal break, 12″ drop, 97.8 mphFF98 mphSlider: 32% usage, 0″ horizontal break, 33″ drop, 88.4 mphSL88 mphSinker: 9% usage, 10″ horizontal break, 20″ drop, 95.8 mphSI96 mphCurveball: 5% usage, 3″ horizontal break, 44″ drop, 82.3 mphCU82 mphSweeper: 5% usage, 9″ horizontal break, 31″ drop, 84.8 mphST85 mphSplit-Finger: 2% usage, 11″ horizontal break, 28″ drop, 91.6 mphFS92 mph less drop ↑ more drop ↓ · horizontal break ↔ · dot size = usage · break incl. gravity MITHRANDIR · CHARTS
PitchUsagePitchesStuff+Status
FB 47.1% 146 104 limited sample
SL 34.5% 107 111 limited sample
SI 11.9% 37 98 limited sample
CB 6.5% 20 96 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' 1"
Weight205 lb
Debut2024-09-08
Live layer

Delta / regression

ERA Δ+2.37
K% Δ+0.006

positive regression

Regression watch

Unlucky so far. Better days ahead.

1.6σ gap
wOBA-against (actual)0.388
xwOBA-against (deserved)0.331

Johnson’s wOBA-against sits at 0.388, but the quality of contact underneath says it should be 0.331 — a gap of 0.057, 1.6 standard deviations from the MLB norm over 34 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
Pitching12026-02-24Stuff and strike quality carried the outing
Projection links / recent games

Available detail

Pitcher Projections 202625.3% K | 3.82 ERAProjection
2026-04-20 @ CHC0 ER / 2 K1.0 IP
2026-04-13 vs CHC3 ER / 1 K1.2 IP