The measurements of regressive lag mode (RLM) damping are correlated with theories that include dynamic inflow, quasi-steady stall drag, and three dynamic stall lift models: Leishman-Beddoes, ONERA-EDLIN (Équation Differentielle Linéaire), ONERA-BH (Bifurcation de Hopf). The database refers to an isolated hingeless rotor with three torsionally stiff blades for which the rigid-body flap and lag modes dominate the fundamental blade motions. As its novelty, the investigation demonstrates that the ONERA-BH model lends itself well to accounting for dynamic stall effect in the stability predictions from Floquet theory. In addition, this investigation is based on a comprehensive database with advance ratio as high as 0.55 and thrust level as high as 0.13. Thus, it brings out, on a unified basis, the predictive capabilities of three theories for RLM damping under high-thrust and high-speed conditions, when the rotor experiences appreciable stall. A finding is that under these conditions, the correlation merits significant improvement. The strengths and weaknesses of the database and predictions are included as well. Copyright © 2011 by the American Helicopter Society International, Inc. All rights reserved.