David Sklansky, I'm not really great at calculating odds.
But I do understand the concepts of card odds and pot odds, at
least on a general basis, and I understand what these numbers
mean when I play. I can even boil what you need to know down to
one quick sentence:
Play draws that are hard to hit only
when the pot is large and there are lots of players in it.
That about sums it up, but here's some explanation if you're
interested:
Card Odds
When you want to calculate "card odds", you're calculating what
the odds are that you won't hit your hand. (Odds are always stated
in those terms, really, even when you're talking about other games.
They're always based on the odds that your desired outcome won't
happen.)
The odds of catching pocket aces in a Texas holdem game
are 220 to 1. This means that you'll have pocket aces on average
only once every 221 hands.
Pot Odds
When you want to calculate "pot odds", you're calculating what
kind of payoff you'll receive if you win the pot versus what you're
having to bet. If you have a pot with $2000 in it, and you have to
call a $20 bet in order to play, your pot odds are 2000 to 20, or
100 to 1. (1 betting unit could win you 100 betting units.)
Odds
are just fractions stated in reverse, basically.
Positive and
Negative Expectation
You have a positive expectation when the payoff on a bet is
higher than even money.
You have a negative expectation when the payoff on a bet is lower
than even money.
To calculate this, you need to understand the
odds of winning your bet versus the odds that the payoff is offering
you.
A roulette example: A single number bet in roulette
pays off at 35 to 1. The odds of hitting a single number in roulette
are 37 to 1. Since the odds of winning are lower than the odds your
bet is offering, you're making a negative expectation bet, which
means you're going to lose money in the long run playing roulette.
How it works in poker: The card odds are more or less your
chances of hitting your hand and winning. The pot odds are the
payoff if you win. If the card odds are lower than the pot odds,
you're making a negative expectation bet. If the card odds are
higher than the pot odds, then you're making a positive expectation
bet.
Winning players make positive expectation bets.
A Quick
Example - Drawing to a Flush
Suppose you have AK of hearts as your starting hand. The flop
come 5h - 9h - 2s. You have 4 cards to the nut flush on the flop.
The odds of hitting your flush are based on the 9 hearts left in the
deck versus the other 47 cards in the deck. In other words, the odds
are 47 to 9, but you can simplify that and say that the odds are
about 5 to 1 that you'll hit your hand.
If it costs you $1 to play
in a pot that has $10 in it, then you're getting pot odds of 10 to 1
on your bet. Since you have a 5 to 1 chance of hitting your hand,
you have a positive expectation bet.
Why Card Odds and Pot Odds
Are Only Part of the Picture
Poker is a game of incomplete information. You don't know what
cards your opponents are holding. This makes betting strictly on a
card odds versus pot odds basis a problematic way of playing.
Some
bets might have a positive expectation even if you don't have the
appropriate pot odds to justify the bet. This is because the other
player or players might fold in the face of your bet or raise, and
in that case, you'll win the pot. So this amount has to be added to
your expectation.
In a semi-bluff situation, you might be making a
profitable bet or raise with a calling hand even if you don't have
the pot odds to warrant it because of the additional expectation
added by your opponents' chances of folding.
More
There's a lot more involved in calculating odds than just this.
You have to be able to calculate outs, know when to discount outs,
and read your opponents and calculate how that affects your odds
too. But this article was meant to be an introduction to the
concepts, so I won't get into all of that here. But I'll add
additional articles about those concepts in the future.
More
detailed poker odds and pot odds can be found at this
calculating poker odds page on TightPoker.
If you liked this article, you'll probably also be interested in
the following:
David Sklansky's All-In Tournament System - Information about
the all in or fold system that Sklansky outlines in his
Tournament Poker for Advanced Players book.
Phil Hellmuth's No Limit Starting Hands Suggestions - Which
hands to play preflop, and how to play them, and a little bit of
information about why. For beginners to no limit holdem.
Texas Holdem Starting Hands - An article I wrote about Texas
holdem starting hands. Again, for beginners, this one is more
focused on limit holdem.
Beginners should also be sure to check out the article about
poker hand rankings too.
This page was last updated on January 5, 2006.
