When opponent is getting "correct" odds to draw, why do you bet??

[spaminator101]

the money you have invested in the pot is no longer yours it doesnt matter what you had to put in to the pot

[mosdef]

i know. what i am saying is that you CAN'T claim that the people left in the pot are both making money at the expense of the OTHER players, since they are not involved in the other hand. the point i was trying to make with my example was that there is situation where you can clearly see that the money isn't somehow coming from the other players. the player with the made hand can bet to suck some value away from the player on the draw, but if he bets and the drawer calls, they aren't collecting EV from the other players.

[pzhon]

There are 3 possibilities:

A) Don't bet. EV ~ 8 BB
B) Bet/call. EV ~ 8.6 BB
C) Bet/fold. EV ~ 10 BB

For the EV estimates, I assumed the pot is 10 BB, that the flush hits precisely 1/5 of the time, and that neither player will pay off on the river.

The correct action is B.

Your choice is between (B or C) and A. (B or C) is better for you. You bet because you would be making an error if you don't bet. Your opponent would gain if you don't bet.

Once you bet, your opponent decides between B and C. The correct choice for him is to call, B. You would gain if your opponent makes a mistake and folds.

It is common for people to say that poker is a game of getting your opponents to make mistakes. However, you still have to avoid making your own mistakes. Failing to bet would be a serious error.

[Dave G.]

[ QUOTE ]
i don't think this is correct. what if the pot has been built up by only the two players involved? how does it make sense that they are now winning money from themselves, and thereby simultaneously winning and losing? it doesn't.

[/ QUOTE ]

This doesn't matter. If that's really what has happened, then all of the flush draws actions were -EV to begin with. However, from this point, all his calls are +EV. The important point is that the total expectation of his play is still negative.

So in this case, he's not winning money at all, but calling increases his expectation due to the money in the pot nonetheless. It makes his play less -EV, but it's still a losing play.

[OrianasDaad]

Given the situation you describe, both players are making money in this situation.

The difference in EV you are looking for as a zero-sum situation arises earlier in the hand.

Clearly, the person on a flush draw made a mistake by even entering the pot when someone else had AA, assuming it was heads-up pre-flop. If it were a multi-way pot, the "dead money" that makes this situation +EV for both players may have come from someone who isn't contesting the pot anymore.

That's the funny thing about Holdem. Since the hand values tend to run fairly close in value EV-wise (with a few obvious exceptions), this type of situation comes up rather frequently in multi-way pots that become heads-up.

It's not an obvious answer, and one that I struggled with for quite awhile. The book you are trying to remember is "Theory of Poker. The theory you quote is "The Fundamental Theorem of Poker".

Lastly, you bet because it's got a higher EV than not betting. Plain and simple. You win a bigger pot when your opponent misses the flush.

[teddyFBI]

Well thanks for the replies; given the somewhat back and forth discussion, it at least reassures me that this wasn't a completely donktastic question, even if the theory behind it is rather straightforward.

Ironically, i have a probability degree from a top university, and simple problems like this still give me headaches.

[jason_t]

The replies in this thread are pretty frustrating since no one has correctly explained the fallacy in

[ QUOTE ]
One of Sklansky's theorums (i forget from which book) states that any time one opponent is "making" money, another one is "losing"...so given that he's getting the correct odds to call you're bet, why is it that it's still advantageous for you to bet (which it obviously is).

[/ QUOTE ]

The key is that the sum of the EVs must be zero; this doesn't mean that both players are losing money.

Say villain holds a draw will come in 20% of the time. If I bet and he calls then my EV is

.8 (1) - .2 (1) = .6

and for him it's

.2 (1) - .8 (1) = -.6.

Hence the sum of the EVs is zero.

Hence, if I am Hero, I am gaining money on my bet.

Now let's take this a little further and suppose the pot is 10 bets.

Then Hero's EV is

.8 (11) - .2 (1) = 8.6

and for villain it's

.2 (11) - .8 (1) = 1.4.

The sum of these EVs is 10. Who is losing 10 here? The pot!

I hope that clears things up.

[BritNewbie]

[ QUOTE ]
donktastic

[/ QUOTE ]

I love that word.
Is it copyright?
If not, I'm going to start using it a lot. (In reference to my own play, especially, the way things have been going lately.)

[PairTheBoard]

You make money when you get your opponent to make a mistake. While he is not making a mistake to call your bet, he is Even More not making a mistake when he calls your Check. Calling your bet is closer to being a mistake than calling your Check.

Put another way, your opponent makes money from you when you make a mistake. Not betting is your mistake.

PairTheBoard

[mockingbird]

I agree

When you bet you are increasing your EV, so not betting is a mistake. When your opponent calls, his EV desreases but is still positive so his not calling is a mistake.

Say a $400 pot and $50 bet. You win 80% of time.

No Bet:

your EV is 4 X 400/5 = 320
his EV is 1 X 400/5 = 80

A bet and call:

your EV is 4 X 450 - 50/5 = 350
his EV is 1 X 450/5 - 4 X 40/5 = 50

So a bet and a call is still EV for both players. And, just as DS says, the additional money you win means your opponent wins less, although still wins.