Mithrandir Metrics
Pitcher projection 2026 Refreshed Sep 5 06:00 AM ET
Pitcher projection / PIT · 2026

Mattson, Isaac

Run-prevention profile built on workable command

Primary
22.2% K%
Range
16.8% to 29.2%
Live Δ
yes
Team PIT Archetype Balanced reliever Age 31 Status Healthy / active roster
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.

2026-09-05
23
Pitching
percentile
Pitching9 metrics
20
Arsenal5 metrics
35
Rolling projection

Preseason / current pace / Bayesian update

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

Pending

Rolling player projection appears after current-season Statcast and projection joins refresh.

Current percentile strip

Actual percentile with projection tick

100th = best in MLB.

2026-09-05
Pitching · percentile strip
WHIP1.59
11
ERA4.91
29
BB%10.9%
27
K%20.7%
40
xwOBA allowed0.373
6
Barrel allowed11.9%
5
Fastball velo94.1
44
Hard-hit allowed50.8%
0
Whiff%19.1%
21
Mithrandir+

Stuff+ and arsenal context

Stuff+ appears when the current pitch-event scoring artifact includes this pitcher; Arsenal Decomposition remains descriptive support under Stuff+.

2026-09-05
Fastball Stuff+101
41
Changeup Stuff+94
9
Curveball Stuff+107
98
Mithrandir Stuff+100
27
Slider Stuff+84
1
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 72%Top usage
ride armside gloveside +Arsenal gap +Shape contrast
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 Mattson, Isaac · Live snapshot series; true 50/100 PA windows require PA-level logs LG AVG 0.313 0.373 2026-08-25: 0.3732026-08-26: 0.3732026-08-27: 0.3732026-08-28: 0.3732026-08-29: 0.3732026-08-30: 0.3732026-08-31: 0.3732026-09-01: 0.3732026-09-02: 0.3732026-09-03: 0.3732026-09-04: 0.3732026-09-05: 0.373 2026-08-25 2026-09-05 xwOBA allowed MITHRANDIR · CHARTS
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 Mattson, Isaac · Aggregate zone metrics; not pitch-by-pitch locations Edge: 33%33%Zone: 51%51%Whiff: 19%19%Called strike: 15%15%First pitch strike: 46%46%Hard hit allowed: 51%51% 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 Mattson, Isaac · 2026 arsenal snapshot 4-Seam Fastball: 71.9%Slider: 11.6%Changeup: 9.6%Sweeper: 6.9% FF72% · 94 mphprimary pitch FF 72%SL 12%CH 10%ST 7% MITHRANDIR · CHARTS
Mithrandir Metrics PITCH MOVEMENT Parameterized Mithrandir chart rendered as SVG for templates and exports. Pitch Arsenal Mattson, Isaac · 2026 arsenal snapshot 12″24″36″48″ 4-Seam Fastball: 72% usage, 1″ horizontal break, 13″ drop, 94.1 mphFF94 mphSlider: 12% usage, 1″ horizontal break, 36″ drop, 84.3 mphSL84 mphChangeup: 10% usage, 8″ horizontal break, 31″ drop, 85.9 mphCH86 mphSweeper: 7% usage, 3″ horizontal break, 41″ drop, 82.9 mphST83 mph less drop ↑ more drop ↓ · horizontal break ↔ · dot size = usage · break incl. gravity MITHRANDIR · CHARTS
PitchUsagePitchesStuff+Status
FB 79.5% 333 101 qualified
CH 9.5% 40 94 limited sample
SL 6.0% 25 84 limited sample
CB 5.0% 21 107 limited sample
Method note

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

Model read

Projection notes

1
templated note
Needs the arsenal to hold up against lefties (0.274 vs 0.247 xwOBA allowed split).
pitcher
2
templated note
Volume stays relief-shaped even when the bat-miss traits are strong.
pitcher
3
templated note
Home park gives the run-prevention profile a small HR cushion.
pitcher
4
templated note
Primary mix entering the season: 4-Seam Fastball 78%, Changeup 12%, Slider 9%.
pitcher
Live context

Current-season signal

ERA Δ--
K% Δ--
Sample37.7 IP

negative regression

Projection table

Point projection and range

MetricPointRangeHalf-width
Innings34.1----
Batters Faced141----
K%22.2%16.8% to 29.2%+/- 6.2%
BB%10.1%6.8% to 14.8%+/- 4.0%
Whiff%21.8%16.6% to 26.8%+/- 5.1%
HR/91.190.32 to 1.79+/- 0.74
xwOBA Against0.3170.264 to 0.348+/- 0.042
Barrel% Allowed7.6%3.5% to 11.3%+/- 3.9%
ERA4.381.67 to 5.65+/- 1.99
FIP4.102.98 to 7.09+/- 2.05
WHIP1.3860.927 to 1.609+/- 0.341
Platoon / Shape
vs LHH

123 career BF

xwOBA0.274
K%19.6%
BB%11.2%
Barrel6.9%
vs RHH

148 career BF

xwOBA0.247
K%20.8%
BB%7.5%
Barrel6.1%