ABBA is better all the times when there is an even number of players, but if the number is odd ABAB is better in most cases (not all, it's like 97%) an example with 15 players (I multiplied all ratings by 100): set of 15 ratings: [47, 70, 100, 108, 148, 182, 210, 221, 245, 251, 269, 298, 334, 383, 386] ABAB team1 [386, 334, 269, 245, 210, 148, 100, 47] team2 [383, 298, 251, 221, 182, 108, 70] total average: 216, axis: 217, allies: 216, diff:1 ABBA team1 [386, 298, 269, 221, 210, 108, 100] team2 [383, 334, 251, 245, 182, 148, 70, 47] total average: 216, axis: 227, allies: 207, diff:19 You also assumed K/D is a measure of player skill, according to what I've seen it doesn't always work properly. It was supposed to be a sort of ELO but if it hasn't been changed from when I saw it, I think it's a very dubious algorithm. It doesn't take many factors into account (weapons for example, I think old etpub took that into account, then you have backshooting, crossfire, etc.etc.) and once you have a low rating it's very hard to improve it even if you play better, while people who get high scores in lame ways don't go down...