Mithrandir Metrics
Player Houston Astros Refreshed Jul 17 06:00 AM ET
Player profile / Houston Astros

Kai-Wei Teng

P · Bats/Throws R/R · 6' 4", 241 lb · Age 27

Cards
7
Modules
1
Live Δ
yes
Club Houston Astros Position P Roster Active Status Healthy / active roster
Traditional line

Season by season

3D Pitch Lab Projections
WLERAGGSSVIPSOWHIP
2024009.8240011.072.09
2025246.3787029.2391.55
2026464.362310064.0631.36
3 Seasons6105.5035170104.21091.49
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
41
Pitching
percentile
Pitching9 metrics
45
Arsenal6 metrics
56
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 preseason5.28
ERA current pace4.36
ERA rolling p504.78
Observed weight55%
ERA
2.68 3.67 4.78 5.88 6.87
FIP
3.23 3.75 4.32 4.90 5.42
K%
19.8% 21.3% 22.9% 24.6% 26.1%
BB%
7.4% 8.4% 9.6% 10.7% 11.7%
Live percentile strip

Current traits vs projection tick

100th = best in MLB.

2026-07-17
Pitching · percentile strip
WHIP1.34
47
ERA4.36
41
BB%9.7%
36
K%22.1%
47 -15 vs proj
xwOBA allowed0.330
33 -19 vs proj
Barrel allowed7.0%
62
Fastball velo93.4
32
Hard-hit allowed40.6%
38
Whiff%25.3%
70
Mithrandir+

Stuff+ and arsenal context

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

2026-07-17
Mithrandir Stuff+104
68
Slider Stuff+110
93
Changeup Stuff+99
30
Curveball Stuff+102
45
Fastball Stuff+99
25
Sinker Stuff+105
73
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 Teng, Kai-Wei · Live snapshot series; true 50/100 PA windows require PA-level logs LG AVG 0.314 0.330 2026-07-06: 0.3302026-07-07: 0.3302026-07-08: 0.3302026-07-09: 0.3302026-07-10: 0.3302026-07-11: 0.3302026-07-12: 0.3302026-07-13: 0.3302026-07-14: 0.3302026-07-15: 0.3302026-07-16: 0.3302026-07-17: 0.330 2026-07-06 2026-07-17 xwOBA allowed MITHRANDIR · CHARTS
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 34%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 Teng, Kai-Wei · Aggregate zone metrics; not pitch-by-pitch locations Edge: 37%37%Zone: 48%48%Whiff: 25%25%Called strike: 18%18%First pitch strike: 47%47%Hard hit allowed: 41%41% 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 Teng, Kai-Wei · 2026 arsenal snapshot Sweeper: 34.2%4-Seam Fastball: 27.8%Sinker: 16.3%Changeup: 10.2%Curveball: 9.7%Slider: 1.9% ST34% · 84 mphprimary pitch ST 34%FF 28%SI 16%CH 10%CU 10%SL 2% MITHRANDIR · CHARTS
Mithrandir Metrics PITCH MOVEMENT Parameterized Mithrandir chart rendered as SVG for templates and exports. Pitch Arsenal Teng, Kai-Wei · 2026 arsenal snapshot 15″30″45″60″ Sweeper: 34% usage, 2″ horizontal break, 38″ drop, 84.4 mphST84 mph4-Seam Fastball: 28% usage, 3″ horizontal break, 18″ drop, 93.5 mphFF93 mphSinker: 16% usage, 8″ horizontal break, 26″ drop, 93.3 mphSI93 mphChangeup: 10% usage, 13″ horizontal break, 32″ drop, 87.2 mphCH87 mphCurveball: 10% usage, 10″ horizontal break, 49″ drop, 82.5 mphCU82 mphSlider: 2% usage, 0″ horizontal break, 35″ drop, 85.5 mphSL85 mph less drop ↑ more drop ↓ · horizontal break ↔ · dot size = usage · break incl. gravity MITHRANDIR · CHARTS
PitchUsagePitchesStuff+Status
SL 35.9% 269 110 qualified
FB 26.3% 197 99 limited sample
SI 16.3% 122 105 limited sample
CB 11.9% 89 102 limited sample
CH 9.6% 72 99 limited sample
Method note

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

Reference layer

Current snapshot

Age27
Height6' 4"
Weight241 lb
Debut2024-03-31
Live layer

Delta / regression

ERA Δ-0.53
K% Δ-0.022

positive regression

Regression watch

Unlucky so far. Better days ahead.

0.3σ gap
wOBA-against (actual)0.339
xwOBA-against (deserved)0.330

Teng’s wOBA-against sits at 0.339, but the quality of contact underneath says it should be 0.330 — a gap of 0.009, 0.3 standard deviations from the MLB norm over 65 IP. The results have been worse than the process deserves; as the sample grows, expect the numbers to climb back toward the underlying level.

Mithrandir coverage

Module shelf

ModuleCardsLatestSignal
Pitching72026-06-27Sweeper played up through ST/FF tunnel quality
Projection links / recent games

Available detail

Pitcher Projections 202624.3% K | 4.89 ERAProjection
2026-04-14 vs COL1 ER / 2 K1.1 IP
2026-04-11 @ SEA0 ER / 2 K0.2 IP
2026-04-08 @ COL0 ER / 1 K1.1 IP
2026-04-07 @ COL1 ER / 0 K0.2 IP
2026-04-04 @ ATH0 ER / 3 K2.1 IP