Heat maps of the number of inner (left column) and outer (right column) iterations as functions of radius and time after bounce, from spherically symmetric core-collapse simulations. Rows correspond to different nonlinear solver tolerances and iteration strategies: the top row shows results for tol = 10⁻⁶ with Anderson acceleration (M_outer = M_inner = 2); the second row shows tol = 10⁻⁸ with Anderson acceleration (M_outer = M_inner = 2); the third row shows tol = 10⁻⁸ with Picard iteration (M_outer = M_inner = 1); and the bottom row shows tol = 10⁻¹⁰ with Anderson acceleration (M_outer = M_inner = 2). In each panel, the shock radius (solid black line), the PNS radius (dashed black line), and the ρ = 10¹⁴ g cm⁻³ contour (dashed black line) are indicated.