Mithrandir Metrics
Pitcher projection 2026 Refreshed Sep 26 06:00 AM ET
Pitcher projection / COL · 2026

Mejia, Juan

Late-inning arm with usable miss-bat shape

Primary
24.9% K%
Range
20.6% to 33.6%
Live Δ
yes
Team COL Archetype Balanced reliever 2 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.

2026-09-26
22
Pitching
percentile
Pitching9 metrics
43
Arsenal5 metrics
37
Rolling projection

Preseason / current pace / Bayesian update

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

2026-09-26
ERA preseason3.93
ERA current pace5.40
ERA rolling p504.78
Observed weight58%
ERA
3.41 4.06 4.78 5.50 6.15
FIP
3.24 3.64 4.08 4.52 4.92
K%
19.0% 20.5% 22.2% 23.9% 25.4%
BB%
9.2% 10.2% 11.3% 12.5% 13.5%
Current percentile strip

Actual percentile with projection tick

100th = best in MLB.

2026-09-26
Pitching · percentile strip
WHIP1.70
7
ERA5.40
18
BB%12.2%
17 -25 vs proj
K%20.4%
37 -33 vs proj
xwOBA allowed0.332
29 -32 vs proj
Barrel allowed3.7%
95 +39 vs proj
Fastball velo96.8
85
Hard-hit allowed39.1%
46
Whiff%22.4%
49 -20 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+.

2026-09-26
Fastball Stuff+96
15
Mithrandir Stuff+99
25
Slider Stuff+102
55
Changeup Stuff+100
34
Sinker Stuff+103
56
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 54%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 Mejia, Juan · Live snapshot series; true 50/100 PA windows require PA-level logs LG AVG 0.313 0.332 2026-09-12: 0.3382026-09-13: 0.3392026-09-14: 0.3392026-09-18: 0.3342026-09-19: 0.3342026-09-20: 0.3342026-09-21: 0.3292026-09-22: 0.3292026-09-23: 0.3292026-09-24: 0.3292026-09-25: 0.3292026-09-26: 0.332 2026-09-12 2026-09-26 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 Mejia, Juan · Aggregate zone metrics; not pitch-by-pitch locations Edge: 38%38%Zone: 46%46%Whiff: 22%22%Called strike: 16%16%First pitch strike: 49%49%Hard hit allowed: 39%39% 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 Mejia, Juan · 2026 arsenal snapshot 4-Seam Fastball: 54.0%Sweeper: 37.5%Sinker: 4.6%Changeup: 2.1%Slider: 1.9% FF54% · 97 mphprimary pitch FF 54%ST 37%SI 5%CH 2%SL 2% MITHRANDIR · CHARTS
Mithrandir Metrics PITCH MOVEMENT Parameterized Mithrandir chart rendered as SVG for templates and exports. Pitch Arsenal Mejia, Juan · 2026 arsenal snapshot 12″24″36″48″ 4-Seam Fastball: 54% usage, 0″ horizontal break, 18″ drop, 96.9 mphFF97 mphSweeper: 37% usage, 1″ horizontal break, 40″ drop, 83.9 mphST84 mphSinker: 5% usage, 10″ horizontal break, 23″ drop, 96.0 mphSI96 mphChangeup: 2% usage, 9″ horizontal break, 25″ drop, 93.2 mphCH93 mphSlider: 2% usage, 1″ horizontal break, 33″ drop, 87.9 mphSL88 mph less drop ↑ more drop ↓ · horizontal break ↔ · dot size = usage · break incl. gravity MITHRANDIR · CHARTS
PitchUsagePitchesStuff+Status
FB 50.0% 451 96 qualified
SL 42.0% 379 102 qualified
SI 5.2% 47 103 limited sample
CH 2.8% 25 100 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
Volume stays relief-shaped even when the bat-miss traits are strong.
pitcher
2
templated note
Home park slightly inflates the home-run risk band.
pitcher
3
templated note
Primary mix entering the season: 4-Seam Fastball 67%, Sweeper 33%, Changeup 0%.
pitcher
Live context

Current-season signal

ERA Δ+1.21
K% Δ-0.044
Sample69.3 IP

positive regression

Projection table

Point projection and range

MetricPointRangeHalf-width
Innings36.8----
Batters Faced157----
K%24.9%20.6% to 33.6%+/- 6.5%
BB%9.6%6.0% to 14.0%+/- 4.0%
Whiff%25.2%21.5% to 32.9%+/- 5.7%
HR/91.210.63 to 1.85+/- 0.61
xwOBA Against0.3040.262 to 0.341+/- 0.040
Barrel% Allowed7.1%3.8% to 10.3%+/- 3.3%
ERA4.192.63 to 6.46+/- 1.92
FIP3.913.01 to 5.36+/- 1.17
WHIP1.3631.073 to 1.695+/- 0.311
Platoon / Shape
vs LHH

126 career BF

xwOBA0.258
K%20.3%
BB%10.3%
Barrel5.3%
vs RHH

135 career BF

xwOBA0.241
K%25.4%
BB%6.9%
Barrel5.4%