Reduce the chance that excellent players rank lower than poor players because of poor lottery.
. Because the contestants will be eliminated if they lose two games, it takes 2*N-1(or 2*N-2 if the winner has never lost) to decide the champion for a game with 2 * n contestants.
The winner may lose only one game in the final, but he lost the championship. But it is generally believed that this result is acceptable, because the winner plays fewer games than the loser, which is equivalent to several rounds of bye. One of the ways to make up for it is to completely lose and eliminate, and then decide the champion in one game.
The double-loss elimination system is relatively complicated, which may be difficult for first-time contestants to understand.
Too many times in the same battle group (for example, in 2009, world baseball classic fought Japan and South Korea as many as five times).