Can anyone please explane GameBattles and MLG to me?

If you already know how to work gamebattle's then thats the first step :) But the best way to get good players who are serious is just play online and find people who get good scores in games and go for the objective in the game. Then send a message asking if there intrested in Joining a gamebattle's clan. Thats how i made my clan and were a really good team. Best things to look for are Good player and goes for objectives.