Cloud, 4:1 is 20% odds because it's 1/5... 1:1 would be 50% odds, or 1/2... savvy? When I'm at the table I think like this...
I have a flush draw (assume nut). Villain bets pot. I'm getting 2:1, but need 4:1 to call because I really only have ~20% chance to hit my card on the turn. Can I induce two more bets of that size out of my opponent when the card hits? What about one bet twice the size? After the turn, I also have the river card to extract value. This can be helpful for bet sizing. If I'm on the turn for the river, the necessary bet size on the river may be so high that he won't call it, so I can't go flushing.
I have a flush draw (assume nut). Villain bets pot. I'm getting 2:1, but need 4:1 to call because I really only have ~20% chance to hit my card on the turn. Can I induce two more bets of that size out of my opponent when the card hits? What about one bet twice the size? After the turn, I also have the river card to extract value. This can be helpful for bet sizing. If I'm on the turn for the river, the necessary bet size on the river may be so high that he won't call it, so I can't go flushing.