CHSH optimality conjecture for the Bell singlet state

The Bell singlet state is the maximally entangled two-qubit state used in the standard CHSH experiment. An experiment's statistical strength measures the strength of its evidence against local-realist theories.

CHSH optimality conjecture. The best experiment with the Bell singlet state is the CHSH experiment.

This conjecture asks for the strongest nonlocality experiment obtainable from the Bell singlet state, optimizing the experiment's settings and setting distribution. The paper presents it as a conjecture based on numerical investigations, with no proof supplied, so it remains open.