Whether or Where? Tail Calibration Signals Finite-Budget Reward Hacking in Best-of-N Selection.

arXiv:2610.34375v1 Announce Type: cross Abstract: Best-of-N (BoN) inference returns the candidate with the highest proxy reward, so a larger $N$ tests the proxy's extreme tail more than its average ranking quality. We show that the exact BoN value is a Beta-we