Win a King of The Hill or Kill The Man With The Ball game (Split-Screen, System Link or Xbox Live) and get more time with the ball/in the hill than all your opponent's times added together.
NOTE: You can give yourself this achievement by signing in three guests and starting either a KOTH or KTMWTB split-screen game. When the game starts go to the hill/ball and just hold it/stand in the hill for a few seconds. To pick up the ball you simply have to walk over it. Then end the game and you should get the achievement.
IMPORTANT: You must go to Help & Options --> Settings --> Content Packs and select Jjaro Netmap Pack in order to be able unlock this achievement.