You must be reading this because you are the worst PVPer the Minecraft world has ever seen. Either that or you win by hiding in a cave. Well say no more to that! Here is how you win a HG round using nothing more than your brain.

Step 1:
If you are under fire from a bow, than a perfect dodging method is to swipe around aimlessly, and they can't land a direct hit. They may give in or run out of arrows and take out a close combat weapon, so be prepared for that.

Step 2:
If you are able to successfully sneak up behind an opponent, then don't just take out a random weapon and hit him. You need to examine his armor and decide wether you should use a bow or a battle axe, with an equivalent level sword. NEVER just wing it.

Step 3:
This is what happens most in the games: Close combat. But be sure to stay clear of powerful opponents until you have found iron, gold or diamonds from another player or chest and make a sword with armor. (ALWAYS make a sword FIRST!) Then try to sneak up and go all-out on that bastard.

This method has worked for me many times, and hopefully they will work for you too.

-Flameraven50