This is a discussion on Thinking Ahead within the online poker forums, in the Learning Poker section; You're in a pot with two other players. You have a good hand to win, but the flop shows a possible flush. To drive out
You're in a pot with two other players. You have a good hand to win, but the flop shows a possible flush. To drive out the bad guys, you know the odds of filling a flush are 4/1, so in a pot of say, $400, you would need to bet $150. However if the first guy calls there is now $550 in the pot and the second player is now getting odds of 3.66/1. So your initial bet of $150 is too low. You need to have raised your first bet to $200 to drive both players out. Forget about driving out more than two players, it is uneconomical
I think the better option here to play like you dont have a flush and raise a 150$ on the 3rd flop, and on the last hand you could go for bet pot if you got a flush. in this way they will think that you hadn't a flush and they will call. forcing them to call you is better than forcing them to out.
If you bet $150 into $450, your opponent with a flush draw still likely has the implied odds to correctly call. In other words, he doesn't need 4:1 on the flop since if he makes his flush at the turn, he'll win at least a little more money on average.
I do agree though that if you're betting to protect your hand on a coordinated flop, you might adjust your bet-sizing some depending on the number of players in the hand.