with identity I prefer my antag matches like this:
Within 2-3 minutes it should be clear who wins. Don't make it a shitshow, the other side should surrender.
Reasoning: Everybody is looking for good points at the end of the month (that's why I antag now), if they give me a 10, then I'll no longer select that map as antag for a month. If they muddy my victory to a 6-7, then I might come back.
Similar for me, if I mistakenly join the wrong map, or if I clearly loose, I either help them or leave, letting them win.