# Baseline-skill addendum for the sixteen frozen recovery predictions — registered

**Date:** 10 August 2026. **Status:** REGISTERED at commit; the comparison is computed
only after this file's commit. **Label, stated plainly: outcome-informed
registration.** The holdout was revealed on 6 August and the sixteen outcomes are
published; registration here prevents analytical flexibility in the comparison (nulls,
losses, and aggregation fixed before any baseline score is computed) but cannot
restore outcome blindness — the same honest label as the record's other post-reveal
analyses. What makes the exercise meaningful is that QUINCUNX's side is FROZEN: the
sixteen predictions were sealed on 6 August and cannot move.

## 1. Question

Do the frozen point predictions carry skill beyond simple procedures a reader would
call obvious? Two null classes, fixed here:

- **Null A — visible-analogue carry-forward:** predict the hidden half's statistic by
  the visible half's same statistic. **Declared now: for most targets QUINCUNX's own
  frozen point IS this null** (the registered method computed the visible-half
  analogue), so Null-A skill is zero by construction wherever prediction and null
  coincide; the table marks those rows ≡ rather than pretending a contest. Where the
  frozen method differed from raw carry-forward (the bootstrap-mean count targets),
  both numbers publish.
- **Null B — structure-blind aggregate:** for the four stratified targets only (the
  two non-Latin strata, the two marble strata) — predict BOTH strata at the visible
  half's undifferentiated aggregate rate (non-Latin aggregate as frozen at 2.4161;
  the visible-half aggregate marble share among material-attributed records, computed
  from the visible provinces at scoring time by the registered query below). This is
  the null that tests what the engine's structural differentiation added; it is the
  only place a "recovery beyond the obvious" claim could live, and it is where the
  claim is tested.

## 2. Loss, skill, aggregation — fixed

Per target: absolute error in the target's native unit. Skill per target where a
distinct null exists: **skill = 1 − |error_QUINCUNX| / |error_null|** (positive =
QUINCUNX closer; negative = the null closer; undefined if the null's error is zero,
reported as such). No significance testing: sixteen correlated outcomes on one split
support no error-rate claim, and none is made — the registered deliverable is the
per-target table plus the four Null-B skill values and their median. Both-publish:
the table publishes whatever it shows, including any target where a null beats the
frozen prediction.

## 3. Registered queries

Null B's marble aggregate: visible-half (33 registration provinces) marble share
among material-attributed records, same field definitions as the frozen B7 targets.
All other numbers come from the sealed prediction file and the countersigned scoring
file; nothing else is consulted.

*Registered by the orchestrator; computation follows in a separate commit.*
