Numbers of collisional families for different critical perihelion distances q_crit at which comets break up and disruption probabilities p_crit during one time step (Δt = 500 yr). In the top panel, we vary q_crit while keeping p_crit = 1 constant. In the bottom panel, q_crit = 1.5 AU is constant and we vary p_crit. We always show the number of catastrophic disruptions with parent-body sizes D_PB ≥ 100 km (red line) and 200 km (black line). The error bars indicate typical (1-σ) spreads of Boulder simulations with different random seeds. The observed numbers of corresponding families are indicated by thin dotted lines.