"Open only to players that completed the endgame at least once"

Who's that guy that told you? I recall that the championship has special functions, I just forgot exactly which. Normally, you play your best to get to the center. You sim and try to get 1 hit kills, and when attacking bases, try hitting either CY or Defense facility. Either that, or dealing as much damage as you can while having low repair costs. You would then jump from alliance to alliance, especially during later stages as most players quit. So instead of 20 competing alliances, you are down to 4 plus a few wings.