Transformed radius (R_t) vs. T_*. Models with R_t<200 R_⊙ are in the dense-wind regime, i.e., with higher Ṁ and optical spectra crowded with emission and P Cygni features (shaded region). The colored texts in the lower part of the diagram name the wind-solution regions identified in the T_* sequence. The 1-BiSJ and the 2-BiSJ are indicated by the dotted and dashed lines in the transitions from a valley to a plateau (i.e., increase in Ṁ) toward lower T_*.