I think the best defense is James Toney type rolling the shoulder and blocking. I know guys say moving the head is great, but when a guy gets older that head stops moving, and even if it moves a little less that is enough to get hit hard. Having a jab and blocking it and rolling the shoulder is better and the use of experience can actually make a guy more defensive later than he was when he was young, but the head movement like Mike Tyson had was great until Mike got less motivated. Then guys started to hit him more, and also Tyson used his head movement to slip inside and land body shots, when he stopped using his head movement he started to get hit more since he was not on the inside as effectively and the guys were not as off balance for his counter shot, and he was on the outside in the range of his opponents.