You are right about the probability of success in aftershock sequences, Canie, and
somehow that must be weighted in. By the way, a successful prediction for
a Ml 2.7 or greater aftershock given the current Anza sequence would still be
impressive given the weak aftershocks at the moment. (None above Ml 2 in more
than a day and a half - strange after a Ml 5.1, though. I hope it doesn't mean what
it might in terms of the size of the next quake in the area).