Mithrandir Metrics
Pitcher projection 2026 Refreshed Jul 17 06:00 AM ET
Pitcher projection / STL · 2026

Romero, JoJo

Run-prevention profile built on workable command

Primary
22.4% K%
Range
17.4% to 30.2%
Live Δ
yes
Team STL Archetype Volatile contact Age 30 Status IL-15
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
54
Pitching
percentile
Pitching9 metrics
46
Arsenal5 metrics
54
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 preseason3.63
ERA current pace3.35
ERA rolling p503.51
Observed weight44%
ERA
2.03 2.73 3.51 4.29 4.99
FIP
1.86 2.68 3.59 4.50 5.32
K%
19.2% 21.1% 23.2% 25.3% 27.2%
BB%
5.9% 7.0% 8.3% 9.6% 10.7%
Current percentile strip

Actual percentile with projection tick

100th = best in MLB.

2026-07-17
Pitching · percentile strip
WHIP1.28
58
ERA3.35
68
BB%8.3%
56
K%24.0%
60
xwOBA allowed0.337
27 -27 vs proj
Barrel allowed8.0%
45
Fastball velo93.9
41
Hard-hit allowed43.2%
23
Whiff%21.5%
38 -33 vs proj
Mithrandir+

Stuff+ and arsenal context

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

2026-07-17
Sinker Stuff+101
42
Changeup Stuff+94
9
Fastball Stuff+102
48
Mithrandir Stuff+105
75
Slider Stuff+112
98
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 44%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 Romero, JoJo · Live snapshot series; true 50/100 PA windows require PA-level logs LG AVG 0.314 0.337 2026-07-06: 0.3332026-07-07: 0.3332026-07-08: 0.3332026-07-09: 0.3302026-07-10: 0.3272026-07-11: 0.3272026-07-12: 0.3292026-07-13: 0.3292026-07-14: 0.3372026-07-15: 0.3372026-07-16: 0.3372026-07-17: 0.337 2026-07-06 2026-07-17 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 Romero, JoJo · Aggregate zone metrics; not pitch-by-pitch locations Edge: 38%38%Zone: 45%45%Whiff: 21%21%Called strike: 22%22%First pitch strike: 52%52%Hard hit allowed: 43%43% 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 Romero, JoJo · 2026 arsenal snapshot Sinker: 44.1%Sweeper: 36.3%Changeup: 17.7%4-Seam Fastball: 1.9% SI44% · 94 mphprimary pitch SI 44%ST 36%CH 18%FF 2% MITHRANDIR · CHARTS
Mithrandir Metrics PITCH MOVEMENT Parameterized Mithrandir chart rendered as SVG for templates and exports. Pitch Arsenal Romero, JoJo · 2026 arsenal snapshot 12″24″36″48″ Sinker: 44% usage, 4″ horizontal break, 30″ drop, 93.9 mphSI94 mphSweeper: 36% usage, 4″ horizontal break, 40″ drop, 83.0 mphST83 mphChangeup: 18% usage, 12″ horizontal break, 37″ drop, 87.2 mphCH87 mph4-Seam Fastball: 2% usage, 3″ horizontal break, 18″ drop, 94.5 mphFF94 mph less drop ↑ more drop ↓ · horizontal break ↔ · dot size = usage · break incl. gravity MITHRANDIR · CHARTS
PitchUsagePitchesStuff+Status
SI 42.6% 205 101 qualified
SL 37.4% 180 112 limited sample
CH 17.9% 86 94 limited sample
FB 2.1% 10 102 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
Plays better against lefties right now (0.249 vs 0.298 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: Sweeper 37%, Sinker 32%, Changeup 22%.
pitcher
Live context

Current-season signal

ERA Δ-0.26
K% Δ+0.016
Sample44.7 IP

negative regression

Projection table

Point projection and range

MetricPointRangeHalf-width
Innings38.7----
Batters Faced163----
K%22.4%17.4% to 30.2%+/- 6.4%
BB%8.6%5.2% to 13.0%+/- 3.9%
Whiff%25.7%21.0% to 31.3%+/- 5.1%
HR/91.150.26 to 1.62+/- 0.68
xwOBA Against0.3100.263 to 0.357+/- 0.047
Barrel% Allowed7.6%3.9% to 12.0%+/- 4.0%
ERA3.610.87 to 5.04+/- 2.08
FIP3.682.33 to 7.20+/- 2.43
WHIP1.2360.955 to 1.568+/- 0.306
Platoon / Shape
vs LHH

310 career BF

xwOBA0.249
K%24.4%
BB%7.5%
Barrel4.3%
vs RHH

550 career BF

xwOBA0.298
K%20.6%
BB%8.5%
Barrel8.6%