Prove both on total bases -- and find that my own fix destroyed the backtest

Nothing passed. Nothing promoted. Counter byte-identical.

THE BLOCKER, which is the real finding. statcast_aggregates is upserted in
place and holds exactly one as-of date. Yesterday's skill backtest was honest
only by accident: the nightly refresh was unreachable code, so the profiles
sat frozen at 2026-07-21 -- before the settled window. Repairing that cron was
right for production and it refreshed them to today, destroying every prior
version. Scoring a 2026-07-25 game now uses a season aggregate that contains
that game. Point-in-time validation is structurally impossible from that
table, so every number in this run is contaminated and directional, and none
of it is a gate verdict.

Fixed forward: statcast_history retains a dated snapshot on every refresh, so
point-in-time becomes "as_of_date < game_date, most recent". Retention is
best-effort and cannot fail the refresh; both properties are unit-tested. It
has one day of data, which is not yet a window.

SOLO BASELINE, n=383, Bonferroni across 12 tests (alpha 0.00417): nothing
passes. hard_hit_pct is closest at marginal r 0.135 with p 0.0080, failing
both the 0.15 effect bar and the corrected alpha. And it drifted DOWN from
0.153 at n=295 -- an estimate regressing as noise averages out, not an effect
firming up. I called that number encouraging yesterday; on 88 more rows it is
fading, and it should not keep being quoted at its best value.

INTERACTIONS, each scored by partial correlation against the counter residual
controlling for both of its own components: none pass. Only barrel x power
archetype has an incremental exceeding its parts (-0.101 against 0.019) at
n=260 -- the shape Discipline 2 predicts, but a lead, not a finding.

A methodological catch worth keeping. The archetype conditioner was first
built as barrel_pct over league barrel -- a monotone transform of one of its
own components -- so the "interaction" was barrel squared, measuring
nonlinearity in barrel rate rather than any archetype effect, and it produced
this run's only positive result. A Gauss-Jordan pivot test does not catch that,
because the two columns differ by a scale factor. Fixed with a scale-free
collinearity check plus real archetype labels joined from model_snapshots.
Without it this document would have reported a fabricated interaction as the
session's finding.

COMBINED vs COUNTER on total bases: 0.2718 against 0.2647, delta +0.0071, CI
[-0.065, +0.079] -- inconclusive, and the first time a challenger has not
lost. The same engine on hits was -0.116 with a CI excluding zero. That
contrast is the whole argument for total bases, and it is what the physics
said: contact quality governs extra bases, not whether a grounder finds a hole.

Also built: the compound TB projection. skillProjection no longer refuses
total bases -- a deterministic bases-per-hit multiplier had made P(TB>=2)
exactly P(hits>=1), a relabelled hits curve. It is now a convolution over
per-PA base outcomes with hit-type shares shifted by skill. Non-degeneracy is
locked by test.

4,204 tests green (334 suites); web build exit 0.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01W1sivYNqY2TS5ftykmHBU9

BUILD-STATE.md

@@ -3,6 +3,30 @@
 ## Last Updated
 2026-08-03
 
+## Session 82 (2026-08-03) — TB solo+interactions; point-in-time validation unblocked ✅
+Spec: `specs/tb-solo-and-interactions.md`. 4,204 tests / 334 suites green, build
+exit 0, counter byte-identical.
+- **BLOCKER FOUND + FIXED FORWARD:** `statcast_aggregates` keeps ONE as-of date
+  (upsert in place). Yesterday's backtest was clean only because the refresh was
+  dead code and the table sat at 2026-07-21; fixing the cron destroyed the
+  window. New `statcast_history` table + retention on every refresh (best-effort,
+  never fails the refresh). Until it accrues, all skill results are CONTAMINATED.
+- **SOLO (n=383, Bonferroni-12): nothing passes.** hard_hit_pct marginal r=0.135
+  (p=0.0080) fails both the 0.15 bar and α=0.00417 — and DRIFTED DOWN from 0.153
+  at n=295. Everything else <0.09.
+- **INTERACTIONS: none pass.** barrel×power_archetype is the only one whose
+  incremental partial (−0.101) exceeds its parts (0.019), at n=260. A lead.
+- **Caught a fabricated finding:** the archetype proxy was a transform of barrel
+  itself, so the "interaction" was barrel² — it produced the only positive result
+  until a scale-free collinearity check + real `model_snapshots.archetype` labels
+  replaced it.
+- **COMBINED vs COUNTER on TB: 0.2718 vs 0.2647, delta +0.0071, INCONCLUSIVE** —
+  the first challenger that did not LOSE (hits was −0.116, CI excluding zero).
+- **BUILT: compound TB projection** (per-PA bases convolution, barrel→HR share,
+  exit velo→XBH share). Replaces the refusal; non-degeneracy locked by test.
+- **Next:** let statcast_history accrue a point-in-time window (~a week) while TB
+  reaches n>=500 (~117 short), then re-run. Do not re-run hits.
+
 ## Session 81 (2026-08-03) — The gate, built and run: hits is dead, total bases is the stat ✅
 Spec: `specs/stagea-gate-result.md`. 4,200 tests / 334 suites green, build exit 0.
 Counter byte-identical (zero diff on probabilityEstimator/analyzeViaEngine1).