View Full Version : Calculation of probability of a flush draw

12-21-2003, 12:35 AM
Hand is Ah xh,
flop is xh xh (any other card not a heart)
Probability of drawing the flush:

Everybody knows its 1/4 + 1/4 = 50% right?

My calculation seems to be about as dumb and I don't understand why.

I think the proper formula is
(1-((47-9)/47)*((46-9)/46)) = 1-(36*35/47*46) = 1-.583 = .417

But all the charts I see say it's ~.36

Would one of you math buffs show me the error of my ways, please?

D /images/graemlins/crazy.gif

12-21-2003, 02:16 AM
47-9=38 and 46-9=37 so the result should be 1-(38*37/47*46)
or 378/1081 or about 0.34968.

12-21-2003, 11:32 AM
I was so worried about the formula, I forgot how to subtract. I knew this was dumb, just not that dumb.