Surface gravity as a function of equilibrium temperature of HJs listed in Table 4. Circle, square, and diamond symbols represent planets observed in high resolution, low resolution, and both, respectively. The orange, purple, and blue shaded regions indicate regions of parameter space proposed by T. G. Beatty et al. (2017b) to host planets with inverted or isothermal, ambiguous, and monotonically decreasing P-T profiles, respectively. Note that T. G. Beatty et al. (2017b) cast these in terms of the dayside brightness temperature T_B, which is a measured quantity not equal to the theoretical quantity T_eq, which we use; however, their relation has only a weak dependence on temperature so the difference should be small. The yellow and teal dashed lines show the boundary found by V. Parmentier et al. (2018) for the presence of TiO and H⁻, respectively; these species should be present above and to the right of these lines.