I searched around here and the web to find out how this works but seem to get contradicting info. If my question has already been answered in another thread, I apologize.

When calculating percentage of improving, I was using the rule of 4 and 2 (# of outs times 4 postflop, # of outs times 2 post turn) as seen in this video. http://www.youtube.com/watch?v=kn97ymhgp_w&feature=fvw

Then I have found some sites claiming the correct way is the rule of 2 and 4 (# of outs times 2postflop, # of outs times 4 post turn)

As if that wasn't enough to have me doubting myself I find this...

http://www.texasholdem-poker.com/odds_chart
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Pretty much outs time 2 to give u postflop % chance of improving and outs times 2 again to give u post turn% chance of improving, then added together to determine ur % for both turn and river combined.

What gives?


What I was doing was this and someone please correct me if I'm wrong.
If I had a diamond flush draw on the flop (4 to a flush) I calculated 9 possible diamonds times 4 which equals 36%. I then divided 100 by 36 which gives me 2.7 - 1 = 1.7 to 1. Meaning that I will make my flush 1 time every 2.7 times I try by the turn. I need to get aleast 1.7 to 1 pot odds to justify calling. If by the turn, I don't improve, I have a 18% chance of making my flush by the river. 100 divided by 18 = 5.5 - 1 = 4.5 to 1. I need at least 4.5 to 1 to justify my draw.

Which one is correct?? The rule of 4 and 2? The rule of 2 and 4? Or the info found on http://www.texasholdem-poker.com/odds_chart


Thank u

The rule of 4 and 2 is a simplification of the chart you found at http://www.texasholdem-poker.com/odds_chart. It is so you can calculate to a pretty accurate number when you don't have an odds chart handy.

You use the rule 4 if you expect to be able to see both flop and turn, and just the rule of 2 if you are calculating for odds of improving on the next card.

Umm kinda have no idea what you said for any of that and I didn't read any of the links, but here is the answer:

First, the rule is an estimate and becomes a bit inaccurate at some points, especially the more outs you have.

If you want to know the approximate percentage that you will hit your out ON ANY GIVEN STREET (TURN OR RIVER) then it is 2% * amount of outs. So for your flush you are approximately 18% to hit it on the turn. If you don't hit it on the turn, you're also about 18% to hit it on the river. Combined is 36%.

If you want to know the chances of hitting on EITHER the turn OR the river, then it is 2% x outs + 2% x outs = 4% x outs. 4% x 9outs = 36% ... the same percentage we got the other way.


Now something to remember, if you use the Rule of 4 ... then you are figuring out your percentages to hit it on EITHER the turn or River, so you have to consider how much you have to pay on BOTH the flop and turn in order to compare pot odds. Since this isn't easily done, the rule of 4% x outs is best done when contemplating an allin decision.

Hope that helps.

We could also talk about implied odds, but that's a whole other matter.

Got it... good info