Counting percentages

[AnArkhos]

I was wondering that on what are the percentages base on?

I mean that I know how to count percentages after the flop and before the river, but the real math behind it is a mystery.

Howcome its 4 times the outs after the flop for example?

Anyone?

[liladypokerpro]

That's a good question I always wondered that myself. Here is a good site that offers a lot of helpful information for people who need help with percentages and odds:

Poker Math 101: Pot Odds and Counting Outs

They explain a lot in detail although I am not sure they fully explain the 4x rule.

[emoneypitt]

Originally Posted by AnArkhos I was wondering that on what are the percentages base on? I mean that I know how to count percentages after the flop and before the river, but the real math behind it is a mystery. Howcome its 4 times the outs after the flop for example? Anyone?

4x the number of outs for your percentage odds is a general rule of thumb.

Texas Holdem Poker Odds - After Flop Outs Odds Chart

As you can see here, it is a good indicator.

[irishpkr]

As I see it, after the flop comes down, there are 52 - your 2 cards - 3 flop cards = 47 unknown cards in the deck. So each card at this stage represents 1/47 ie roughly 2%. As for the 4%, if you consider having one out, what is the chance of missing that one out with 2 cards to come? The odds of hitting your card is 2% on one street, thus the chance you miss is 98%. And the chance of missing on both turn and river? 98% x 98%, which turns out to be 96%, ie 4% chance to catch one card on the next two streets.

Hope that clears things up and isnt totally mathmatically incorrect

[TheyNeverLearn]

well i always wondered when they count percentages do they take in consideration the other cards that were dealt out to other players and also do they take in consideration the burn cards also?

[frob23]

Originally Posted by TheyNeverLearn well i always wondered when they count percentages do they take in consideration the other cards that were dealt out to other players and also do they take in consideration the burn cards also?

No, and you can't. You only count the cards you can see. If you're up against 8 people or 1 person... you're still only seeing 5 cards on the flop (2 in your hand and 3 on the board) and those are the only 5 you can remove from the 52 card deck when running the numbers.

Now, in the case of TV where they know all the cards that are out... that's a different matter and they can run numbers for a much smaller unknown deck. Or when you're heads up and can see the other person's card... then you can count them but the betting is over anyway at that point.

Burn cards are unknown, just like your opponent's cards, and can't be counted. A lot of people try and count odds by removing the number of cards from the deck that are out or are in the burn/discard pile. They assume that, because they can't draw those cards they don't effect the play, but as long as you haven't seen the cards... the cards in the discard or an opponent's hand may as well still be in the deck for all you know. If you assume odds for a 9 card flush draw against a 5 opponents as 9/37 and not 9/47 ... you're going to be finding out the hard way how badly that mistake in figuring your odds will hurt you.

The first shows a 3.1-1 chance against hitting, the second (and correct one) a 4.2-1 chance against. If you're drawing like you'll hit nearly 25% of the time and not 20%... it's going to catch up with you.

[liladypokerpro]

Originally Posted by emoneypitt 4x the number of outs for your percentage odds is a general rule of thumb. Texas Holdem Poker Odds - After Flop Outs Odds Chart As you can see here, it is a good indicator.

I think we can all agree that 4x is the rule of thumb, but I think his question was why is it the rule of thumb? I think he was asking where they came up with that?

[irishpkr]

I thought I explained that in my previous post :P

[liladypokerpro]

Originally Posted by irishpkr I thought I explained that in my previous post :P

BEAR WITH ME I'M FIGHTING THE FLU AND THE FEVER HAS GOT MY BRAIN ALL FRIED LOL

[AnArkhos]

Originally Posted by irishpkr As I see it, after the flop comes down, there are 52 - your 2 cards - 3 flop cards = 47 unknown cards in the deck. So each card at this stage represents 1/47 ie roughly 2%. As for the 4%, if you consider having one out, what is the chance of missing that one out with 2 cards to come? The odds of hitting your card is 2% on one street, thus the chance you miss is 98%. And the chance of missing on both turn and river? 98% x 98%, which turns out to be 96%, ie 4% chance to catch one card on the next two streets. Hope that clears things up and isnt totally mathmatically incorrect

Thnx. Makes sense at least.

I know haow to count my percentages from the flop onward, but I was, like the lady there pointed out, intrested to know the details of the equasion.

Now on to the river odds:
I've seen 2 ways to count the river card percentages.

One is (your outs)x2 + 2 % -> An open ender would thus have: 8x2+2=18% to hit on the river

The other is just (outs x2)%

Which one is more correct? And why?

[irishpkr]

I thought it was always (2xouts) +1 on the river, I think this is simply because now there are only 46 unknown cards, so the odds of hitting one card are slightly above 2% (2.1739% to be more accurate), so if you take for example 7outs, you have 2.17x7= roughly 15% to hit

[AnArkhos]

Lol.

Ok then. I know 3 ways to count the river card odds.

I must say that it's very intresting to see that most players I know, don't know these odds. Some of the ones that make good profit out of poker usually do.

One dude knows them by heart. He doesn't know how to count them, but gives the odds from the top of his head and they are correct. Years of poker.

[frob23]

Originally Posted by AnArkhos Now on to the river odds: I've seen 2 ways to count the river card percentages. One is (your outs)x2 + 2 % -> An open ender would thus have: 8x2+2=18% to hit on the river The other is just (outs x2)% Which one is more correct? And why?

Well, I can run some sample numbers and find out:

# of outs: 2*outs, 2*outs+2%, Real Percentage
-------------------------
15 outs: 30%, 32%, 32.6%
10 outs: 20%, 22%, 21.7%
7 outs: 14%, 16%, 15.2%
4 outs: 8%, 10%, 8.7%
2 outs: 4%, 6%, 4.3%

So... from this, I can assume that the more outs you have the more accurate it is to add 2%. The less outs, the less accurate. In short, they're both right.

At the table, I almost never think this way about outs. To be honest. On the river, I am thinking "46 / outs minus 1". So when I have 10 outs... I am thinking 3.6-1 (3.6 to 1 ... in all the following numbers the "-" means "to" and not "minus") against hitting my hand. For 15 outs... roughly 2-1 against. 4 outs... 10.5-1 and so on. These numbers aren't perfectly accurate either but they work for me and are instantly usable when looking at the size of the pot and the size of the bet to see if I am getting the right pot odds or close to the right implied odds.

For example: If I have 9 outs and the pot is 350 and someone bets 100... I am being offered 4.5-1 pot odds and my draw is just about 4-1 (a little worse but only a little)... so I can make the call. Often, it's not nearly as close so you're not worried about absolutely perfect precision.

[AnArkhos]

Seems that the closest would be that (2xouts)+1 then..