Holdout-Promotion Bake-off — Decision Simulator

#2555 · the 4-clause rule that decides whether a challenger skill replaces the champion. playground

Bake-off inputs

Champion composite 7.0

Challenger composite 7.8

Margin (incumbent wins ties) 0.5

Lock min_pass (sealed bar) 7.0

rubric composite.min_pass = 5.5 — NOT consulted (lock wins)

Challenger regresses a dimension below its min_blocker Holdout hash matches the lock (un-tampered)

Decision

PROMOTE

The LOCK's min_pass (7.0) is the authoritative composite gate, deliberately stricter than the rubric's day-to-day 5.5 floor. A challenger that clears the rubric's bar can still fail the sealed holdout bar — that's the anti-gaming point. The harness fix in this PR makes the lock win (it previously let the rubric override).

Scenario — copy back into Claude