Estimated Einstein radius, density slope and lens finding probability. Top: 68% probable values of ${\theta }_{\mathrm{E}}^{(\mathrm{est})}$ and density slope γ of the SLACS lenses, where ${\theta }_{\mathrm{E}}^{(\mathrm{est})}$ is defined in Equation (2). Bottom: 68% credible region of the lens finding probability, defined in Equation (35). The correlation between ${\theta }_{\mathrm{E}}^{(\mathrm{est})}$ and γ makes so that lenses with overestimated γ are more likely to be included in the sample.