4 replies to this topic

[Pokerdad2222]

Sorry to take up space with whats probably an easy question so somebody point me in the right direction. I can easily calculate odds for the river but How do I do it for the turn and river? For example a flush draw with 9 outs. On river it would be outs by cards left in deck for one of those nine to hit. How do you figure this out with two to come??

[custom36]

Newbie questions are always welcome here. If you flop a flush draw, you're 35% to hit it on the turn. If you miss the turn, you're about 20% to hit it on the river. You'll usually need about 2.5:1 pot odds on the flop and about 4:1 on the turn (I think) to mathematically justify a call without taking implied odds into consideration.Yeah, that explanation kinda sucked, but it should suffice until one of the regulars gets in here.

[UglyJimStudly]

Real quick approximation: take the number of outs you have, double that number, and multiply by the number of cards still to come. The result is in the ballpark of the percentage you'll hit an out.Example: you flop a four-flush and expect you need a flush to win. You have 9 outs to the flush, with two cards to come. 9x2x2 = 36, chance of hitting if you call to the river is approximately 36%, expressed as odds you're a little better than a 2-1 shot. If the turn's a brick, you're about 4-1 to hit on the river (9x2x1 = 18%).This calculation is an approximation that's good enough for most purposes so long as you give yourself a little breathing room.

[MrNiceGuy]

Custom36 said:

Newbie questions are always welcome here. If you flop a flush draw, you're 35% to hit it on the turn. If you miss the turn, you're about 20% to hit it on the river. You'll usually need about 2.5:1 pot odds on the flop and about 4:1 on the turn (I think) to mathematically justify a call without taking implied odds into consideration.Yeah, that explanation kinda sucked, but it should suffice until one of the regulars gets in here.

Correct, except that as you said it's 35% after the flop, which is about 2-1 (not 2.5-1); this assumes that you're going to see the river no matter what, which is usually the case in limit, but generally isn't the case in NL unless it's an all-in situation.

Pokerdad2222 said:

On river it would be outs by cards left in deck for one of those nine to hit. How do you figure this out with two to come??

To mathematically calculate it with two to come, you figure out the odds of not hitting on either street, and subtract this from 1. So for a flush draw, the odds of missing all nine outs on the turn is 38/47, and the odds of missing again on the river is 37/46, so the answer is: 1 - (38/47 * 37/46) = 35%A quick way to approximate the percentage is to multiply your outs by 2, and then multiply again by the number of cards to come. 9*2*2 = 36%

[Pokerdad2222]

Thanks for the help. i knew it was pretty simple but I just wanted to make sure I had it right.ThanksE