Illustrated Guide To Texas Hold'em: Making Winners Out Of Beginners

I'm a big fan of this book, as it has helped me make the jump from beginner to skilled player. Therefore I was surprised to see a negative review of Purdy's odds calculation. As I use his system when I play, I of course went back to the book to see look at it closely. And guess what? It turns out that the reviewer was actually wrong, and this book is correct. The confusion lies in the difference between odds and probability, and understanding the difference is crucial if you attempt to use either at the poker table. Let's go back to the example the review used. You have pocket cards of 6-8, and the flop is 2-3-8. What are the odds that an 8 will come on the turn? Purdy claims 45 to 2, and the reviewer claims 2 in 47. Who's right? Purdy is. You see, Purdy is calculating the odds, whereas the reviewer is calculating the probability. Let's make this much simpler. Pretend you have a situation where there are fifteen cards left, out of which 5 cards will give you the result you desire. (I know you'll never have this few cards left in Hold 'Em, but it's easier to understand this way). Your instinct would be to say that your odds are 15 to 5, and then reduce that to 3 to 1. But that's not calculating odds, it's calculating probability. Odds are formed by this setup: [Number of cards that are not what you desire] to [number of cards that give you the desired results]. So out of 15 cards left, 10 give you the undesired result, whereas 5 give you the desired result. Therefore, the odds are 10 to 5, or 2 to 1. Much different, right? If you want to get more complicated, you can use this formula, which translates probability to odds: where x = probability, 0.x/(1-0.x) = odds. Try it yourself. If something has a 20% chance of happening, the odds of it happening are .25, or 4 to 1. Weird, but true. So why all this high-level discussion for what's supposed to be a beginner book? It's about learning to use odds quickly. The whole point is: compare the odds of getting the card you want to how much money you're going to get back for the bet. You can get the same answer by calculating the probability, but that's much harder to do while sitting a poker table. Using odds, if you're playing against 9 other people, after the flop there will always be 47 unseen cards. All you need to do is subtract the number of out cards you have, then put the result on the left, the number of out cards on the right, and you have your odds. Do the same with the amount in the pot vs. what bet you need to call, and you have your pot odds. If you try to use probability, you're going to be doing a lot of division in your head, and under pressure you risk messing it up. The math wizards can do this, most of us can't. So, overall this is a fantastic book for beginners, and one that I highly recommend. Trust that the author has this right. And if you're still unsure, check it out yourself.