Question about flush draw outs

[jackblack73]

You're not making an assumption that there are no clubs in anyone elses hand. You're assuming other's have clubs in the same ratio as would be otherwise distributed in the deck.

Let's say there are 8 other players, so that's 16 cards out. It's reasonable to assume that there are 3 clubs among those 16 cards. So whether you do 9/47 or 6/31, you get essentially the same probability.