WillerZ: Surely it is best for Black to play a here, making 2 eyes and removing a liberty from the surrounding white group. You would only play b if you really wanted to show someone the death of a rabbitty six for some reason.
WillerZ: Forget I said that -- Bc, Wa, Bb, Wd, Bb is the correct sequence. That'll teach me to count liberties before posting.