Mithrandir Metrics
Player Chicago Cubs Refreshed Jul 17 06:00 AM ET
Player profile / Chicago Cubs

David Peterson

P · Bats/Throws L/L · 6' 6", 240 lb · Age 30

Cards
15
Modules
1
Live Δ
yes
Club Chicago Cubs Position P Roster Active Status Healthy / active roster
Traditional line

Season by season

3D Pitch Lab Projections
WLERAGGSSVIPSOWHIP
20241032.9021210121.01011.29
2025964.2230300168.21501.37
2026476.451911182.1701.64
7 Seasons41374.391501261705.06841.40
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.

2026-07-17
17
Pitching
percentile
Pitching9 metrics
25
Arsenal6 metrics
41
Rolling projection

Preseason / current pace / Bayesian update

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

2026-07-17
ERA preseason3.97
ERA current pace6.45
ERA rolling p505.55
Observed weight64%
ERA
4.39 4.94 5.55 6.16 6.71
FIP
3.48 3.80 4.15 4.50 4.82
K%
17.0% 18.1% 19.3% 20.4% 21.5%
BB%
7.8% 8.5% 9.2% 10.0% 10.6%
Live percentile strip

Current traits vs projection tick

100th = best in MLB.

2026-07-17
Pitching · percentile strip
WHIP1.65
8
ERA6.45
7
BB%9.5%
39
K%18.0%
18 -19 vs proj
xwOBA allowed0.352
14
Barrel allowed6.0%
75 +20 vs proj
Fastball velo92.0
16
Hard-hit allowed44.0%
18
Whiff%20.6%
30 -24 vs proj
Mithrandir+

Stuff+ and arsenal context

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

2026-07-17
Fastball Stuff+95
14
Mithrandir Stuff+100
36
Sinker Stuff+98
21
Slider Stuff+108
90
Changeup Stuff+104
67
Curveball Stuff+100
19
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 Peterson, David · Live snapshot series; true 50/100 PA windows require PA-level logs LG AVG 0.314 0.352 2026-07-06: 0.3472026-07-07: 0.3472026-07-08: 0.3472026-07-09: 0.3472026-07-10: 0.3472026-07-11: 0.3522026-07-12: 0.3522026-07-13: 0.3522026-07-14: 0.3522026-07-15: 0.3522026-07-16: 0.3522026-07-17: 0.352 2026-07-06 2026-07-17 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.

5Pitches 2026Season 30%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 Peterson, David · Aggregate zone metrics; not pitch-by-pitch locations Edge: 39%39%Zone: 48%48%Whiff: 21%21%Called strike: 16%16%First pitch strike: 50%50%Hard hit allowed: 44%44% 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 Peterson, David · 2026 arsenal snapshot Sinker: 29.7%Slider: 23.8%4-Seam Fastball: 22.6%Changeup: 12.2%Curveball: 11.7% SI30% · 92 mphprimary pitch SI 30%SL 24%FF 23%CH 12%CU 12% MITHRANDIR · CHARTS
Mithrandir Metrics PITCH MOVEMENT Parameterized Mithrandir chart rendered as SVG for templates and exports. Pitch Arsenal Peterson, David · 2026 arsenal snapshot 15″30″45″60″ Sinker: 30% usage, 2″ horizontal break, 25″ drop, 91.9 mphSI92 mphSlider: 24% usage, 0″ horizontal break, 34″ drop, 86.1 mphSL86 mph4-Seam Fastball: 23% usage, 2″ horizontal break, 20″ drop, 92.1 mphFF92 mphChangeup: 12% usage, 12″ horizontal break, 34″ drop, 85.6 mphCH86 mphCurveball: 12% usage, 3″ horizontal break, 49″ drop, 80.6 mphCU81 mph less drop ↑ more drop ↓ · horizontal break ↔ · dot size = usage · break incl. gravity MITHRANDIR · CHARTS
PitchUsagePitchesStuff+Status
SI 28.7% 286 98 qualified
SL 23.9% 238 108 qualified
FB 22.3% 222 95 qualified
CB 13.4% 133 100 limited sample
CH 11.7% 116 104 limited sample
Method note

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

Reference layer

Current snapshot

Age30
Height6' 6"
Weight240 lb
Debut2020-07-28
Live layer

Delta / regression

ERA Δ+2.47
K% Δ-0.027

positive regression

Regression watch

Unlucky so far. Better days ahead.

2.0σ gap
wOBA-against (actual)0.407
xwOBA-against (deserved)0.352

Peterson’s wOBA-against sits at 0.407, but the quality of contact underneath says it should be 0.352 — a gap of 0.054, 2.0 standard deviations from the MLB norm over 90 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
Pitching152026-07-09Sinker played up through FF/CH tunnel quality
Projection links / recent games

Available detail

Pitcher Projections 202620.7% K | 3.98 ERAProjection
2026-04-13 @ LAD4 ER / 7 K5.0 IP
2026-04-08 vs AZ5 ER / 6 K5.0 IP
2026-04-02 @ SF5 ER / 5 K4.1 IP