Figure 2. The ratio of large to small ruptures on and off the main fault, shown schematically in the top panel, leads to the widely observed b-value of 1. In the lower panel, only the largest off-fault ruptures are shown (dashed lines), but there are many more. The triangular slip function shown in this visualization requires that half the deformation occurs on the main fault and half off the main fault, but all slip functions with fault bends, breaks or triple junctions require off fault slip. Credit: modified from Figures 8b and 20a of King (1983)