Mithrandir Metrics
Player Worcester Red Sox Refreshed Jun 15 06:00 AM ET
Player profile / Worcester Red Sox

Zack Kelly

P · Bats/Throws R/R · 6' 3", 231 lb · Age 31

Cards
0
Modules
0
Live Δ
--
Club Worcester Red Sox Position P Roster Reassigned to Minors Status Out / inactive
Traditional line

Season by season

3D Pitch Lab Projections
WLERAGGSSVIPSOWHIP
2024633.97493056.2611.25
2025134.58280035.1351.33
2026023.31170016.1141.29
5 Seasons884.0411530131.11271.31
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.

2026-06-15
50
Pitching
percentile
Arsenal6 metrics
50
Rolling projection

Preseason / current pace / Bayesian update

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

2026-06-15
ERA preseason4.15
ERA current pace3.31
ERA rolling p503.94
Observed weight25%
ERA
2.14 2.99 3.94 4.89 5.75
FIP
2.76 3.40 4.12 4.84 5.48
K%
16.9% 19.4% 22.1% 24.8% 27.3%
BB%
7.0% 8.6% 10.3% 12.0% 13.5%
Live percentile strip

Current traits vs projection tick

100th = best in MLB.

2026-06-15
Mithrandir+

Stuff+ and arsenal context

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

2026-06-15
Changeup Stuff+102
47
Cutter Stuff+106
88
Fastball Stuff+94
10
Mithrandir Stuff+104
66
Sinker Stuff+101
38
Slider Stuff+102
50
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.

6Pitches 2026Season 45%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 Kelly, Zack · Aggregate zone metrics; not pitch-by-pitch locations Edge: 41%41%Zone: 46%46%Whiff: 17%17%Called strike: 17%17%First pitch strike: 32%32%Hard hit allowed: 42%42% 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 Kelly, Zack · 2026 arsenal snapshot Cutter: 44.9%Sweeper: 20.9%Sinker: 15.9%4-Seam Fastball: 14.3%Changeup: 3.4%Curveball: 0.6% FC45% · 91 mphprimary pitch FC 45%ST 21%SI 16%FF 14%CH 3%CU 1% MITHRANDIR · CHARTS
Mithrandir Metrics PITCH MOVEMENT Parameterized Mithrandir chart rendered as SVG for templates and exports. Pitch Arsenal Kelly, Zack · 2026 arsenal snapshot 12″24″36″48″ Cutter: 45% usage, 1″ horizontal break, 26″ drop, 90.7 mphFC91 mphSweeper: 21% usage, 11″ horizontal break, 39″ drop, 81.7 mphST82 mphSinker: 16% usage, 14″ horizontal break, 19″ drop, 95.9 mphSI96 mph4-Seam Fastball: 14% usage, 3″ horizontal break, 14″ drop, 96.1 mphFF96 mphChangeup: 3% usage, 19″ horizontal break, 37″ drop, 83.6 mphCH84 mphCurveball: 1% usage, 6″ horizontal break, 42″ drop, 84.3 mphCU84 mph less drop ↑ more drop ↓ · horizontal break ↔ · dot size = usage · break incl. gravity MITHRANDIR · CHARTS
PitchUsagePitchesStuff+Status
FC 43.8% 124 106 limited sample
SL 21.9% 62 102 limited sample
SI 17.0% 48 101 limited sample
FB 13.8% 39 94 limited sample
CH 3.5% 10 102 limited sample
Method note

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

Reference layer

Current snapshot

Age31
Height6' 3"
Weight231 lb
Debut2022-08-29
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 202622.6% K | 3.98 ERAProjection
2026-04-20 vs DET0 ER / 1 K1.2 IP
2026-04-12 @ STL1 ER / 2 K2.0 IP
2026-04-07 vs MIL0 ER / 0 K0.2 IP
2026-04-05 vs SD1 ER / 0 K1.0 IP
2026-04-04 vs SD0 ER / 1 K1.0 IP