It's very, very old trick, mentioned few times on this forum already. And it works a bit differently.
Trick: *deleted*
Best solution to solve this is to make new slot for every player (set it as 0), and when player respawn in team for the first time in round (this slot is at 0), write number of his team to that slot (1 or 2). Then, when counting multi, don't check current player team, but team which player respawned for the first time (from slot). At round end reset those slots to 0 for every player.
It should be similar mechanism while counting if teams are fair or not in battle game mode. At the end of respawn time in battle, use some troop slot to write current number of players inside team1 and team2. Then when using "are teams fair" script, check this slot, not current number of players. Because right, if there are not many players on the server, you often don't get multi at round end (teams not fair). Even if teams were fair when round started, losing team often loses 2-3-4 players mid round. And that's enough to fail "are teams fair" checking script. It often happens at EU_4 and EU_5, so servers with not so many players playing same time. But from time to time it also happens at EU_1, so fixing that would be nice for every battle server.
*if some admin still don't know how it works, just PM me or check this post editing history (if possible).