Soloman's Formula

the_main

David Soloman, an excellent player from Boston, invented a nice formula for calculating winning chances from a moderate number of outs: multiply the outs by four, then subtract the excess of the outs above eight to get an approximate winning precentage. For example - A flush draw and openended straight draw with 15 outs.

Let x be the wininng precentage

(15)(4)-(15-8) = x
60-7 =x
53=x

Winning precentage is 53%

This could be fun for impressing your friends with your superb math knowledge.

Redington

I have heard about this before. but what if your outs are not above 8?

two over cards to pair: 6

(6 x 4) - (6-8) =

(24) - (-2) = 26

OR IS IT

(24) - (2) = 22

Never mind I just went to figure it out the long way and it is 26% (25.5487)

So you have to used the correct math

-ANTE RIVER-

Does he suggest any variation depending on turn or river?

i.e. you may still have 12 outs after the flop, but if you miss on the turn, your % chance of hitting drops....

ScottyZ

With only one card to come, you use the patented ScottyZ formula

x / 46

where x is the number of outs.

ScottyZ

Hork42

I read about this one on Full Tilt..

# of outs to make your hands multiplied by cards to come. Then multiply by 2. Take the result and a % sign. This is your percent chance to make your draw. Note: this is approximate and not completely accurate, but easier for some people to do, I guess...

Example:

JdTh, Flop Qh 9c 4c. You have an open ended straight draw, with 8 outs. 8 outs with two cards to come gives you sixteen outs. Multiply times two and you will hit the straight approximately 32%. (actual is 31.46%)

Ac8c with same flop. You have 9 clubs left to make the flush. 9x2x2 = 36(%). (actual is 34.97%)

Personally i think calculating odds is for math geeks. I play by how lucky I am feeling at any given moment.

pkrfce9

Oh crap! You need math for this stuff?

The formula mentioned in the OP is for outs after the flop.

To simplify Scottys formula for odds on the turn, double the number then add 8.69565217391304347826086956522% of that value again. Et voila!

doctorbs

If you're willing to trade off a slight variance in the actual % for ease of use, here's what I like to use for quick calculations after the flop.

After Flop:  # of outs x 4 = % of hitting your hand
After Turn:  # of outs x 2 = % of hitting your hand

Example: Flush draw, 9 outs.

After Flop: 9 x 4 = 36%
After Turn: 9 x 2 = 18%

The percentages will be off slightly (even moreso as your # of outs goes up), but it's a nice quick way to figure out ballpark percentages.