Jab Defense 2

This defense is a quick one you simply bring your open hand straight up going either left or right slapping your attackers fist off it's target.  If your sitting and the punch comes from the side you can bring hand up from a face down position and backhand the punch.  It's also good to move your head in the opposite direction when you knock the fist aside for example your left hand goes right your head then goes left.

Jab
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Jab Defense 1

This first defense is done by doing what, i call a side-lean which is done by leaning your upper-body to either side using speed.  Whatever side you lean towards that hand should come to the other side of your jaw or to the front to protect.  To avoid the punch perfectly practice the move while the attackers arm is still bent when he throws.  I believe it's best to lean towards the shoulder of the punch so you won't get hit by the other hand so go to the outside which is the side of the shoulder.

One thing you can do is combine this defense with a sidestep to further get to the outside just to be safe. Both moves must be done at the same time to save time.

Jab
http://tmblr.co/ZjlYGxJr0N75

http://tmblr.co/ZjlYGxJzCE3A

http://tmblr.co/ZjlYGxK9uEq9