[en] The H-mode power threshold has a weak but positive B_T dependence when the ion ∇B drift is away from the X-point, in contrast to the nearly linear B_T dependence when the ion ∇B drift is toward the X-point. This indicates that geometry plays an important role in the H-mode power threshold scaling. A simple model of the ∇B drift effect failed to predict this behavior, but successfully predicted the sign change of gas puffing and low X-point height on the power threshold. The difference between the threshold power required for sawtooth and nonsawtooth triggered transitions can be substantial. This effect may contribute to the observed B scaling of the H-mode power threshold