Six earthquakes (orange stars) greater than magnitude 4.5 have occurred in the Anza, California, region over the last two decades. The maximum earthquake intensity of each mainshock is listed as roman numerals. The largest aftershock of each quake is shown with the grey stars. Also shown is the expected size of the largest aftershocks (yellow stars). In most cases the predicted size is larger than the observed size (grey stars). In general, the largest aftershocks (grey stars) are all about magnitude ~3.5.