How SIQX works

SIQX grades the at-bat, not the box score. Ten decisions a hitter makes at the plate, nine a pitcher forces, scored from Statcast pitch-by-pitch data, ranked against every qualified player, updated daily.

Hitter componentsPitcher componentsValidationPicks and the boardWhat the gap meansPaper

Ten hitter components

FIQ Fastball IQ
In-zone contact and out-of-zone takes, on fastballs only.
DSR Discipline ratio
Walks against strikeouts.
CHS Chase rate
Swings at pitches outside the zone. Lower is better.
ZWP Zone whiff
Missing pitches in the zone. Lower is better.
ZCN Zone contact
Contact on in-zone swings.
OCN Out-of-zone contact
Contact when he does chase.
ZAE Early zone aggression
Swinging at strikes early in the count.
ECC Early count chase
Chasing in early counts. Lower is better.
TSS Two-strike survival
Not striking out with two strikes.
ACW Ahead-count waste
Chasing when ahead in the count. Lower is better.

Every component is a decision, bucketed from raw pitches. Nothing is taken from a leaderboard aggregate. Equal weight, one tenth each. Thin samples shrink toward the league middle: rel = N/(N+K).

Nine pitcher components

HHI hard-hit allowed, OZI chase induced, ZWF zone whiff forced, ZCF zone contact allowed, OCI out-of-zone contact allowed, EZC early zone command, ECI early chase induced, TSP two-strike put-away, AZC ahead-count command. Same rules: decisions the pitcher forces, equal weight, shrunk on thin samples.

Validation

r = +0.31
SIQX vs xwOBA · 1,207 hitter-seasons 2023–2025 · inputs 74210a70aaab9bf3
r = −0.71
PSIQX vs xwOBA allowed · 1,334 pitcher-seasons · inputs c7dbccbe26e92160

These are same-season correlations, re-cut on 2026-09-09 after a score-side fix. They are confirmatory: correlation never chooses or weights a component. The hitter figure has been revised down twice as outcome leaks were found and removed (+0.573 → +0.444 → +0.31); each revision is in the RUNBOOK with the reason.

Forward tests: five pre-registered tests in September 2026 asked whether the components predict future production. They do not, beyond what current production already says. SIQX is a description of how a player is deciding now.

Picks and the board

One moneyline underdog a day when the hitter edge clears +5.0 SIQX points and the pitching gate (starter × 0.6 + bullpen × 0.4) is not below −12.0. Tracked from zero under the pre-registered v14 rules, which do not move when the record is bad. The board adds a two-leg parlay from the pick and the top tracked runner-up, and three props — hitters to record a hit against a weak starter, one per team, no repeats within five days. Every line is logged before first pitch and graded the next morning; the record by market is on the board and on every card.

What the gap means

Buy low / sell high on Analytics is the gap between a player's decision rank and his production rank today. It is the site's fantasy tool. It is a description of where he sits on two lists, and the forward tests above are the honest context for it.

Paper

SIQX: Situational IQ Index (PDF, June 2026) — component definitions, validity audit, bullpen separation. The correlations in it predate the September correction; the figures above are current.