My Current NanoBots Melee entry. It uses an exact box movement pattern (after attempting to run to the bottom of the battlefield), reduced lead aim based on range, exact locking code on the closest opponent, and good fire/energy control to help out last enemy bots. It is a combination of ideas generated from watching Gem, KomoriNinja?, my previous Infinity versions, and a few new ideas to boot.
In detail: The movement is go forward 170 units, stop and turn 90 degrees. Repeat. Most melee bots use either 100% lead aim, 90% lead/circular aim, and no aim. This pattern does a good job of defeating all 3 of them. It also runs to the bottom of the map (or top of atan() fails) to avoid being in the center of the map (and thus getting pounded from all sides.)
The aim is as follows: Take the distance to target divided by 1000. 1 - this value gives us the ratio to lead our target (assuming 3 power shots and where 1 would be full linear, 0 none, -1 full reverse linear.) It works great against other pattern moving bots or dodge bots. It's not as effective against Walls type bots or Antigravity bots.
The lock code scans the field until it's almost time to fire, then locks onto the closest bot we had found up to that point. This is the number 1 reason my bot is so effective.
The fire control is nothing special - download the bot to see it yourself.
Where is the download link?