I need to know why

[James Boston]

I thought I had a good understanding of poker theory. I still don't think I'm clueless. I'm capable of winning more than I lose. But, the more I read these postings, the less I think I know. I need explanations for the things I read. I know that with 2 cards to come, if you're on a four-flush, you're 1.86:1 to make, but I don't know why. I know what EV is, but I don't know how to figure it. What should I read to learn these things. I don't want a chart to memorize. I want to learn how to figure these things out myself. Thanks.

[Nottom]

Read the Theory of Poker

[GuyOnTilt]

Good for you. The fact that you don't just want to memorize stats and phrases that you can recite, but rather learn the how's and why's of poker puts you beyond most players out there. Buy The Theory of Poker by David Sklansky.

You know what, just so I don't sound like I'm taking the easy way out by giving you a book reference, I'll explain how to calculate your odds of hitting a flush draw:

On the flop you have 9 outs, correct? What you really want to calculate here is the probability that you won't hit your draw, and then subtract that from 1. So since there are 9 cards that will help you on the turn out of 47 possible cards that could come, the chances that you won't hit on the turn are 38/47 (~80.6%). Then, assuming you miss on the turn, the odds that you'll won't hit your 9-outer on the river are 37/46 (~80.4%). Multiplying them together gives you the odds of both of these events occurring, meaning you'll miss your draw on both streets ~65% of the time, which means you'll make it ~35% of the time. That's where the ratio 1.86:1 comes from.

Welcome to the boards!

[rigoletto]

Hi James

I concurr with the advice of Nottom and Guy: Buy Theory of Poker!

I also have en easier way than Guy's of calculating the odds of hitting a four flush: You have 9 outs and 47 unknown cards, so you are drawing 9:47 on the turn and 9:47 on the river. Since you draw twice you can just double your outs = 18:47. This is method is valid for all hands you plan to go to the river with.

EV is a little more complicated, since it's dependent on a lot of parameters: cards, position, opposition, potsize, agression/passivity at the table, number og opponents etc. The best way to learn is getting the basics from TOP and then discuss poker a lot (this board is a very effective way of doing that).

[BruceZ]

Check out these posts (http://forumserver.twoplustwo.com/showthreaded.php?Cat=&Number=326125&page=&view=&sb =5&o=&vc=1) for not just one, but three different ways to figure out the odds of making your flush draw by the river (1.86-1 or 35%). Then understand that it is usually more important to know your odds for making your hand on the next card rather than in 2 cards. See this post (http://forumserver.twoplustwo.com/showthreaded.php?Cat=&Number=381698&page=1&view=ex panded&sb=5&o=14&vc=1) for an explanation of why, and an easy way to remember the required pot odds. In addition to Theory of Poker, I also recommend Getting the Best of It for some good discussion of probability and EV.

[Copernicus]

It may also be helpful to realize that the minimum odds you need is the same as a simplified 0 EV calculation, where the simplifications are that you have no folding equity and that if you hit your hand it is a winner.

[t_perkin]

I think if you want a good understanding of statistics and probability (which you seem to, and so you should if you want to be a good poker player). Then I would buy a text book on statistics and probability.
The Theory Of Poker (TTOP) will obviously give you the applications which are specific to gambling and in particular poker. But it is all just basic stats applied to poker. If you understand probability then you will find the concepts in the book straightforward to understand.
If you don't understand the probability before you read the book you will find it much harder to follow.
I would recommend buying a book on Statistics and Probability something such as Schaums outlines: Probability and Statistics. Spiegel, Schiller, Srinivasan , and then read TTOP.

Hope this helps

Tim

P.S.: I am not doing down TTOP, it is an excellent book. But I think that buying TTOP alone is not the easiest way to solve your problem.

[ChipWrecked]

Wish I had studied stats and prob harder in college, instead of moaning about how I'd rather be given an atomic wedgie (Which reminds me, the prof did mention to never play poker against a statitician).

Here's a dummy's (mine) way to figure the probability (close enough for government work): every out is worth about 4%. At around nine or ten it drifts some, but with ten outs I'm flinging chips anyway.

Using this method your chance of hitting the flush is of course 36%, one point off.

Much easier in the heat of battle for me; limping to the flop in the ring game of intelligentsia .

[James Boston]

I appreciate the advice. Between writing the first post and this one, I ordered "Getting The Best Of It." I'll probably order TTOP soon. The advice on odds (along with borrowing a buddy's college stats book) has already helped. Thanks again.

[DrSavage]

[ QUOTE ]
I also have en easier way than Guy's of calculating the odds of hitting a four flush

[/ QUOTE ]
Your calculation is simplier but not exactly correct since you count the flushes which occur when you hit both turn and river twice. Your number of 18/47 is higher than the real odds by around 3.5% as a result.
It's still a decent approximation.

[johnnyhearts]

I agree that your method gives a crude, ballpark estimation that can be used at the table if needed but the gentleman was wanting to know why a flush draw is 1.86/1 to hit on the turn or river. It is:

Chance of hitting the turn + (Chance not hitting the turn x Chance of hitting the river) or:

9/47 + (38/47 x 9/46) = approx. 35% or about 1.86/1

JJ Hearts