Mithrandir Metrics
Pitcher projection 2026 Refreshed Jul 16 06:00 AM ET
Pitcher projection / HOU · 2026

Arrighetti, Spencer

Run-prevention profile built on workable command

Primary
24.1% K%
Range
21.2% to 32.4%
Live Δ
yes
Team HOU Archetype Volatile contact Age 26 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.

2026-07-16
33
Pitching
percentile
Pitching9 metrics
41
Arsenal7 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.

2026-07-16
ERA preseason4.12
ERA current pace4.50
ERA rolling p504.35
Observed weight60%
ERA
3.05 3.66 4.35 5.03 5.65
FIP
3.50 3.97 4.50 5.03 5.50
K%
20.8% 22.1% 23.6% 25.1% 26.5%
BB%
9.4% 10.3% 11.2% 12.2% 13.1%
Current percentile strip

Actual percentile with projection tick

100th = best in MLB.

2026-07-16
Pitching · percentile strip
WHIP1.36
44
ERA4.50
37
BB%12.3%
16 -18 vs proj
K%22.7%
51
xwOBA allowed0.349
16
Barrel allowed8.2%
41
Fastball velo92.3
20
Hard-hit allowed31.5%
92
Whiff%23.3%
53
Mithrandir+

Stuff+ and arsenal context

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

2026-07-16
Curveball Stuff+101
35
Fastball Stuff+104
67
Mithrandir Stuff+102
53
Changeup Stuff+95
12
Cutter Stuff+113
99
Sinker Stuff+105
74
Slider Stuff+101
44
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.

7Pitches 2026Season 33%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 Arrighetti, Spencer · Live snapshot series; true 50/100 PA windows require PA-level logs LG AVG 0.314 0.349 2026-07-05: 0.3342026-07-06: 0.3342026-07-07: 0.3342026-07-08: 0.3342026-07-09: 0.3342026-07-10: 0.3492026-07-11: 0.3492026-07-12: 0.3492026-07-13: 0.3492026-07-14: 0.3492026-07-15: 0.3492026-07-16: 0.349 2026-07-05 2026-07-16 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 Arrighetti, Spencer · Aggregate zone metrics; not pitch-by-pitch locations Edge: 37%37%Zone: 45%45%Whiff: 23%23%Called strike: 17%17%First pitch strike: 45%45%Hard hit allowed: 32%32% 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 Arrighetti, Spencer · 2026 arsenal snapshot Curveball: 33.5%4-Seam Fastball: 28.9%Sweeper: 12.3%Sinker: 10.7%Changeup: 7.4%Cutter: 6.2% CU33% · 77 mphprimary pitch CU 33%FF 29%ST 12%SI 11%CH 7%FC 6% MITHRANDIR · CHARTS
Mithrandir Metrics PITCH MOVEMENT Parameterized Mithrandir chart rendered as SVG for templates and exports. Pitch Arsenal Arrighetti, Spencer · 2026 arsenal snapshot 15″30″45″60″ Curveball: 33% usage, 7″ horizontal break, 53″ drop, 76.6 mphCU77 mph4-Seam Fastball: 29% usage, 3″ horizontal break, 18″ drop, 92.4 mphFF92 mphSweeper: 12% usage, 3″ horizontal break, 42″ drop, 79.4 mphST79 mphSinker: 11% usage, 8″ horizontal break, 23″ drop, 92.1 mphSI92 mphChangeup: 7% usage, 12″ horizontal break, 35″ drop, 84.2 mphCH84 mphCutter: 6% usage, 0″ horizontal break, 25″ drop, 87.5 mphFC87 mphSlider: 1% usage, 7″ horizontal break, 36″ drop, 82.2 mphSL82 mph less drop ↑ more drop ↓ · horizontal break ↔ · dot size = usage · break incl. gravity MITHRANDIR · CHARTS
PitchUsagePitchesStuff+Status
CB 32.3% 273 101 qualified
FB 27.7% 234 104 qualified
SL 14.4% 122 101 limited sample
SI 9.5% 80 105 limited sample
CH 8.4% 71 95 limited sample
FC 7.7% 65 113 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
Primary mix entering the season: 4-Seam Fastball 32%, Curveball 22%, Cutter 14%.
pitcher
Live context

Current-season signal

ERA Δ+0.21
K% Δ-0.014
Sample80.3 IP

negative regression

Projection table

Point projection and range

MetricPointRangeHalf-width
Innings68.4----
Batters Faced307----
K%24.1%21.2% to 32.4%+/- 5.6%
BB%9.8%6.5% to 13.0%+/- 3.2%
Whiff%24.4%20.7% to 31.6%+/- 5.4%
HR/91.450.59 to 1.91+/- 0.66
xwOBA Against0.3320.261 to 0.352+/- 0.045
Barrel% Allowed8.4%5.2% to 11.3%+/- 3.1%
ERA4.292.33 to 5.94+/- 1.81
FIP4.242.61 to 5.38+/- 1.39
WHIP1.3641.056 to 1.624+/- 0.284
Platoon / Shape
vs LHH

451 career BF

xwOBA0.303
K%26.5%
BB%11.8%
Barrel8.7%
vs RHH

390 career BF

xwOBA0.286
K%24.9%
BB%8.4%
Barrel7.3%