builtbykev
4c9707ffbb
Report-only verification of the two unproven claims from the Session-77 wiring, which fired platoon on synthetic split-less hitters where the K=600 regression zeroed the multiplier and masked both direction and resolution. No product code changed — this adds one standing regression test. FIXTURE — Yordan Alvarez (LHB), real 2026 splits, deep both hands: 115 PA vs LHP at .529 slg, 327 PA vs RHP at .695, overall .652. The regression leaves a material multiplier both ways (0.97 vs LHP, 1.023 vs RHP), so unlike the last test this fixture can actually reveal direction. RESOLUTION — verified on the live slate that the pitcher-hand attached to a hitter is the OPPOSING team's probable, not his own. CLE (home) resolved to Minnesota's away starter 696070; MIN (away) resolved to Cleveland's home starter 800048. The chain — hitter's team, the game, the other team, that team's probable, that pitcher's hand — is correct, and it is pinned independently of direction because a backwards resolution is invisible on a neutral hitter. DIRECTION — deterministic L-vs-R on the frozen Alvarez fixture. Facing RHP nudges UP (1.023) because he slugs .695 there, above his .652 overall — a favorable opposite-hand matchup, exactly what platoon theory predicts for a left-handed bat. Facing LHP nudges DOWN (0.97). The two move opposite directions, and crucially the SPECIFIC sides are asserted, not merely "opposite" — a mirrored-but-inverted implementation would put RHP below 1 and fails here. Both- backwards is ruled out. The test also pins a REVERSE-split hitter, Brandon Nimmo, who hits better vs LHP than RHP. His multiplier goes up vs LHP, following his real numbers rather than a hardcoded LHB-vs-RHP assumption — proof the sign is data-driven, which is the correct design. VERDICT: PASS. Resolution correct, direction correctly signed against both the real split and platoon theory. Pinned by tests/unit/platoonPolarity.test.js so the polarity cannot silently regress — the opp_rank_stat lesson applied. Tests 3750 passed / 302 suites. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01VCNgGSt5qvcLxaeQqa7Zpj