I'm trying to approximate the probability of drawing a flush in texas hold-em. The attached image is the expression I think should work. However, it's inconsistent with the odds given for 7-card stud, given here: http://wizardofodds.com/games/poker/ I think the probabilities should be the same. Does anyone know what I did wrong? The link to the expression in wolfram alpha is as follows: http://www.wolframalpha.com/input/?...)-4)+(13+choose+7)(4+choose+1))/(52+choose+7) Thank you!