Recent studies found huge disagreements (about 0.15 to 170) between the measured spin resonance strength εFS and the εBdl predicted by the widely used formulae. This resulted in theoretical disputes over: the correct factor of 2 in the εBdl equations for both rf solenoids and rf dipoles; and then between Gγ and (1 + Gγ) in the rf-dipole equation. Thus, we are systematically studying this problem at COSY. Our recent rf-dipole deuteron data strongly favor Gγ over the widely-used (1 + Gγ) factor for rf dipoles. This is further supported by the precise agreement of our new rfsolenoid deuteron data with the widely used rf-solenoid equation, indicating that our experiment is calibrated correctly. Moreover, these data firmly support the “BNL” factor of 2.