Rule of four and two

Tried to search to see if this had been posted before but couldn't find anything so here goes.

Lots of threads on odds and calculations so I thought I would pass on the easiest way to get your odds while playing. I learned this from my buddy Phil Gordon.

Simple as this: After the flop you times your number of outs by 4 and after the turn you times by 2. Pretty easy huh. So you have 8 outs after the flop, you have about a %32 chance to hit one of your cards and about a %16 after the turn The percentages are always a couple points lower than actual but are close enough and can easily be figured out on the fly.

Nice post Lo-Dog
There were a few threads a ways back about this, probably too hard to find though.
This is a great way of quickly get a rounded fairly accurate calc. of your drawing %s.
For odds instead of percentages:
ex. flush draw on flop: 9 of your suit still live, and 47 (52 - 3 on flop - 2 in your hand) unseen cards. 47/9 = 5.22 so your odds of hitting are 4.22 : 1 by the turn. To get the flop to river odds, i'm lost there. (edited - i got this wrong the first time )
takes some practice to be able to do quickly but is also very helpful if you prefer odds



i personally can't do either of these in the time you get online for your turn...or live for that matter:turtle:

Lo-Dog, this is indeed a great post. I actually read about this on the Full Tilt boards awhile back. It's great to figure out YOUR odds to hit your hand and a GREAT way to calculate how to give your opponent wrong odds to call for their drawing hand.

The rule of 4 and 2 is stated as such to make it simple. But if you want to be even closer on the % for the river, multiply by 2 then add 2.

yeah i've heard same thing, but add 1?
don't know which is the most accurate

smd173 said:

The rule of 4 and 2 is stated as such to make it simple. But if you want to be even closer on the % for the river, multiply by 2 then add 2.

Click to expand...

This is true. I believe on the river adding the %2 makes it almost bang on (less than %1 off). On the turn X 4 is very, very close for less outs and becomes off by a couple % (always on the low side I think - wish I had my book) the more outs there are.

According to this:

http://wizardofodds.com/holdem

-A flush draw after flop is 34.97%
-A flush draw after turn is 19.57%

(outs x 2) + 1 = (9x2) + 1 = (18) + 1 = 19% (post-turn)
(outs x 4) - 1 = (9x4) - 1 = (36) - 1 = 35% (post-flop)

margin of error: +/- 1%

I'm pretty sure this is about as close as it gets. I didn't know about the -1% for post-flop odds, just figured that out after running some odds

This is a great thread!

Thanks everyone. I always wanted to know an easy way of calculating this.

Much appreciated!

Jim