Next, point your body sideways, make a fist with your arm straight until your fist touches the wall, and again measure the distance between the wall and your head. By facing the wall from the side, the average person can hit the wall while their head is 4-6 inches further back from it. In the ring, this translates into a 4-6 inch reach advantage, just by turning to the side. UP - Keeping your hands up means blocking your own vision. Fighters like Prince Naseem Hamed know that keeping your visual field open and maintaining proper distance is more important to defense than keeping up the gloves.
Fencers train constantly to maintain perfect distance.
If one fencer takes a quick step forward, the other fencer takes a quick step back. Playing with the distance creates opportunities to strike, while avoiding being hit at the same time. Great fighters do not bounce on their toes. If you are bouncing upward with your heels off the ground, you can't change direction, and if you can't change direction, you can be timed for a punch. While watching the Shane Mosley-Antonio Diaz fight, I noticed that whenever Diaz bounced or shuffled his feet, Mosley jumped in and smacked him.