Just remember this simple rule:
If you are on the same side you started the game (left or right), your teams score must be even. 0, 2, 4, 6 ...
If you’ve switched sides and are now on the opposite side from where you started, your score is odd. 1, 3, 5, 7 ...
So, just set it once, at the beginning of the game and you are good to go! That's it!