Any conditioned response is better than no response

As pointed out above, if you are trained and mentally prepared for an attack, and you have a pre-made plan how to react to such confrontations, your chances have already increased dramatically. In a confrontation, there is usually no time to think!

A physical attack resembles utter and total chaos. It goes all so quick, and boom, before you know what's happening, you've already got a fist coming your way or a pair of large strong hands around your throat. After this, things usually go rapidly down-hill.

Our natural first response to a physical attack is to withdraw, to move back, to get out of the way. Just look at the animal world. Even the biggest most ferocious animal will at first jump out of the way when a sudden attack occurs, then it will evaluate the enemy and the type of attack, and if the animal feels it stands a chance, it will then engage in a fight and/or counter attack.