this is a VERY effective technique.

ok first, walk up to him and start talking shit or w/e.
then, out of nowhere, put ur hand in his face. He will then automatically put both his hands on his face to try to remove your hand from his face.

When he does that, you drill him right in the solarplexus (in the middle-front of your chest, where your ribs start to seperate. [basically, its directly in the middle of ur nippples,] when you hit him there, you WILL knock the wind out of him for at least 5-10 seconds.) when hes got the wind knocked out of him, he will be DEFENSELESS. so when he bends over trying to get breath, beat the fuck out of his face.

trust me, this WILL work. i am a amatuer boxer and i have gotten many knockouts by hitting my opponent in the solarplexus.