Fractional errors of the maximum likelihood HII bubble center (left) and radius (right) as a function of the number density of the observed galaxies. The black curve corresponds to a single realization of the EoR morphology and galaxy samples. The light (dark) blue region corresponds to the 95th (68th) percentile of fractional errors obtained from 100 realizations. With n_gal≳0.01 galaxies cMpc⁻³, the fractional errors drop below the grid resolution we used to calculate the likelihoods (1.5 cMpc).