[RobNottsUk]

Something noone emphasised, is that the flop call benefits from better odds than the pot odds imply, because it closes the betting round. With 4 opponents already in you have a clear call.

If the turn pairs the board, you wouldn't want generally to draw to non-nut hand.

But if you're on the river made the hand, and can close the betting, it's the chances of it being good, that determines whether the call is correct or not. If the previous betting makes you suspect a set was out there, then you'ld generally fold, unless the pot odds were better, if it seems quiet and unlikely that someone filled up, then you'ld generally call, even if the pot odds were worse due to small pot size.

In general you play tigher on draws if you're exposed to re-raises, bettor to your immediate right and field behind you, and looser when your call closes the betting.

With the nut flush, you migh call sometimes for 1 bet, but not a 2nd (despite improved pot odds), because it becomes clear to you the raiser filled up.