Some of them are listed at LiteRumble.
The important one is APS, as that is the primary ranking. APS is average percentage score.
For each opponent your percent score is 100% * <your score> / (<your score> + <opponent score>). APS is this value averaged over all the battles/opponents for your bot, so it is important not just to win, but to win by the largest margin possible.
PWIN is percentage of wins.