Two profiles go up at a time and you pick the one you would rather look at. Each tap casts a vote and a new pair loads. There is no account, no card and no limit on how many you get through.
Tap the one you would rather look at. Rankings use a weighted score, so one lucky win cannot top the board.
How the scoring works
A battle vote counts as a high score for the winner, which nudges them up the board. Scores are weighted so one lucky win cannot put a profile at the top — a model needs a run of them before the ranking really moves.
Why it is not a straight vote count
Unweighted counts reward whoever has been listed longest. The weighting means a new profile with genuine support can climb past an old one that nobody is voting on any more.