Denominator-Audit Robustness Analysis for Bell/CHSH Statistics: A Reconciliation Study of Strict vs Standard Protocols

We present a denominator-audit framework for Bell/CHSH statistics to disentangle mechanism effects from protocol-bookkeeping effects under a shared data context. The protocol compares strict and standard definitions in parallel and separates evaluation into an engineering gate (computability and basic data sufficiency) and a thesis gate (claim-level preregistered criteria). On the same NIST completeblind event stream, binary CHSH yields S_strict=2.336276 (window 0.0) and S_standard=2.839387 (window 15.0), i.e., Delta=+0.503111 from pairing-rule change alone. Bootstrap (n=2000) gives CI95_strict=[2.295151, 2.378669] and CI95_standard=[2.820420, 2.857413]; because 2sqrt(2)=2.828427 lies inside the standard CI, we do not claim Tsirelson violation. A simulated fallback run also shows that S_standard does not necessarily exceed S_strict, reinforcing protocol sensitivity. We report a method-level, boundary-aware conclusion: Bell/CHSH claims should be interpreted through protocol definitions, uncertainty intervals, and retained negative results, rather than peak statistics alone. Figures may be added in a subsequent version; current evidence is provided via tables and machine-readable result files.