probability between flop and river

[peterc]

I understand the significance of saying there's approx. 20% chance of a flush draw completing on the turn. You need 4 to 1 pot odds to call. But why is it important to know that there is a 36% chance of completing by the river? I still need 4 to 1 pot odds to proceed at each stage.

[Pov]

If you or your opponent are going to be all-in you get to see both cards for the price of one.

It's also useful in terms of current equity in multi-way pots. If you've heard the phrase "pumping a flush draw" this is based on the idea of betting and raising a flush draw for value on the flop against several players because of your pot equity edge.

[stud7champ]

You are right its the rough odds that are required for hand guidance on the value play

[SheridanCat]

While it's correct that at each street the odds are roughly 4:1 against making the hand, it's usual to take your flush draw all the way to the river by calling on the turn as well. That's why it's important to know that your four-flush on the flop is about 2:1 against all the way to the river. That way you can use the 2:1 number when deciding to play on after the flop.

This is called Effective Odds and Sklansky explains it in detail in Theory Of Poker. It's the odds with more than one card to come.

Regards,

T