Distributions of the reduced inverse power metric R (Equation (1)) for the SFR, LCDB, and SSR simulated light-curve populations, separated into the correctly and incorrectly recovered rotational periods. The vertical dashed line shows the confidence threshold R = 0.00994, defined as the value below which at least 99% of SFR periods are accurately recovered (including half/double-period harmonics). Correct fits (blue) concentrate strongly at low R, while incorrect fits (red) populate a broader tail toward larger R, demonstrating that smaller R values correspond with more reliable period recoveries.