[dellcosta]

With all due respect, gamingmouse, your calculations are great, but consider the point in learning of the questioner. He's thinking "There are 13 cards in a suit and 52 cards in a deck, so I've got 25% chance of drawing a suit, right?" I was illustrating the probability in basic terms, beginning with independent events, without throwing the book at him.

That said, Dave H., gamingmouse is correct and here's why. The seemingly simple 25% probability of drawing one of your suits on each turn is affected by the fact that cards have been dealt and you can already see 4 of the suited cards. You know there are 13 suit cards. You're holding 2 of them, and you see 2 on the board, so there are 9 left unseen. Also, you know there are 52 cards in a deck, and you're looking at 5 of them, leaving a total of 47 unseen cards after the flop. Get it so far?

Ok, step back for a few minutes from gamingmouse's equation. If you need just one of the 9 cards out of the 47 unseen cards in the deck, then the probability of drawing one of them on the turn is:

9/47 = 19.1% (not 13/52 = 25%)

If you miss on the turn, there are still 9 of your cards out there, but there's only 46 cards left unseen at this point. So the probability of catching on of your cards on the river is:

9/46 = 19.6%

Following the basic (key word "basic") arithmetic, the probability of drawing one of your cards would be 38.7%. But as gamingmouse alluded with the equation he offered up, there's slightly more to it. It would probably help you to study his equation until the lightbulb goes on.

How's that gamingmouse and AngryCola? Better?