My own rule of thumb is fairly simple: keep on top of what's happening in the confrontation, and when things get to the, uh, point of no return, do not be the one who waits to receive the strike. There's plenty of evidence that preemptive self-defense played a major part in the thinking of some of the greatest MA pioneers (see Abernethy's brilliant article on the actual views about preemptive striking (as vs. the surrounding pieties and virtuous legends) held by masters such as Funakoshi and Musashi Miyamoto).
Strike hard at vulnerable, high-yield targets and, as the chessplayers would say, always keep a tempo ahead—never let the attacker regain a choice in how to respond. I think the ideal model of SD is the forced mate in chess, or the pool player's holy grail of running the table—not letting the opponent get even one shot in. To me, that's the essence of self-defense, once the pre-attack situation has reached the tipping point.
Strike hard at vulnerable, high-yield targets and, as the chessplayers would say, always keep a tempo ahead—never let the attacker regain a choice in how to respond. I think the ideal model of SD is the forced mate in chess, or the pool player's holy grail of running the table—not letting the opponent get even one shot in. To me, that's the essence of self-defense, once the pre-attack situation has reached the tipping point.
