19 replies to this topic

[Norny21]

i know that +EV is positive expected value but i dont know how to apply it or what it really means can some1 give me some examples of +EV and -EV with a good definition

[kes1981]

Go to 2+2 and use their search function. There are alot of good posts on the subject.

[JMoney2681]

i know that +EV is positive expected value but i dont know how to apply it or what it really means can some1 give me some examples of +EV and -EV with a good definition

You're about to have sex with 1 of 2 girls...

Mandy has a huge rack, long legs, great @ss, perfecet tan, nice girl next door smile,and knows how to work it...


Bertha is overweight, smelly, hairy arms and legs, missing teeth, 3 chins, and has a pancake butt..


Mandy= +EV

Bertha= -EV

[LongLiveYorke]

I ask you to play the following game:

I will flip a coin. If it lands heads, I give you $1. If it lands tails, you give me $3. What is the Expectation Value of this game:

Assuming the coin is fair, chance of heads = 50% and chance of tails = 50%

So, EV = (50%)($1) + (50%)(-$3) = .5 - 1.5 = -$1

So the ev of the game for you is -$1. If you play the game, on average, you lose a dollar every time. You will never actually lose a dollar because you can only either win one dollar or lose three. But this is what we expect to win after many trials. In general:

EV = Sum over all possible outcomes of [(probability of an outcome)*(value of that outcome)]

Assuming there is a discrete set of outcomes.

In poker, we can make the same sort of calculations. Let's say we have a flush draw or something and we guess that our hand is 15% to be made on the river from the turn. The pot is $100 and our opponents moves all in for his last $20. Should we call?

15% of the time we get $120 and 85% of the time we lose $20:

(.15)(120) + (.85)(-20) = $1

So, calling has an expectation of $1, so we should call. Every time we call, we win $1. Of course, we could win up to $120, which would at the time make us very happy. But really when we make the call we should only be as happy as we would be if we won $1, because the big payoff is lessened by the many times that we don't win and lose a little.

[Norny21]

I ask you to play the following game:

I will flip a coin. If it lands heads, I give you $1. If it lands tails, you give me $3. What is the Expectation Value of this game:

Assuming the coin is fair, chance of heads = 50% and chance of tails = 50%

So, EV = (50%)($1) + (50%)(-$3) = .5 - 1.5 = -$1

So the ev of the game for you is -$1. If you play the game, on average, you lose a dollar every time. You will never actually lose a dollar because you can only either win one dollar or lose three. But this is what we expect to win after many trials. In general:

EV = Sum(all possible outcomes) of (probability of an outcome)*(value of that outcome)

Assuming there is a discrete set of outcomes.

holy crap i suck at math i get the coinflip thing a lil bit but the EV= thing u lost me there

[navybuttons]

You're about to live with 1 of 2 girls...

Mandy spends all your money, tells her friends all your secrets, flirts with your friends, and generally ignores you...
Bertha does all the cleaning, appreciates you, thinks you're amazing, and wakes you up every morning with a bj..
Mandy= -EV

Bertha= +EV

FYP

[LongLiveYorke]

holy crap i suck at math i get the coinflip thing a lil bit but the EV= thing u lost me there

Don't worry about the sum part. It just means that we add up everything that can happen (as in win or lose, or a number of things if there are many possabilities) and multiplied by probability that they will happen.

Another example:

We play the following game. I roll a dice. If it lands on 1 or 2, I give you $10. If it lands on 6, you give me $15. If it lands on 3, 4 or 5 we tie and nothing happens. We're assuming it's fair and the chance of landing on one side is 1/6:

EV (for you) = (1/6)($10) + (1/6)($10) + (1/6)($0) + (1/6)($0)+ (1/6)($0) + (1/6)(-$15)

= $.83

So, you expect to win about 83 cents every time you play, so you should play as many times as you can. Even though you lose $15 sometimes, you gain $10 more often and in the end you will end up ahead.

[Norny21]

Don't worry about the sum part. It just means that we add up everything that can happen (as in win or lose, or a number of things if there are many possabilities) and multiplied by probability that they will happen.

k that helps a lil more can u show me a sample using poker hands or something poker related so i can apply it to poker

[JMoney2681]

FYP

Nice.

[Acid_Knight]

k that helps a lil more can u show me a sample using poker hands or something poker related so i can apply it to poker

He already gave you an all-in example with a flush draw on the turn.

Scroll up.

[Norny21]

oops sry didnt see that my bad

I ask you to play the following game:

I will flip a coin. If it lands heads, I give you $1. If it lands tails, you give me $3. What is the Expectation Value of this game:

Assuming the coin is fair, chance of heads = 50% and chance of tails = 50%

So, EV = (50%)($1) + (50%)(-$3) = .5 - 1.5 = -$1

So the ev of the game for you is -$1. If you play the game, on average, you lose a dollar every time. You will never actually lose a dollar because you can only either win one dollar or lose three. But this is what we expect to win after many trials. In general:

EV = Sum over all possible outcomes of [(probability of an outcome)*(value of that outcome)]

Assuming there is a discrete set of outcomes.

In poker, we can make the same sort of calculations. Let's say we have a flush draw or something and we guess that our hand is 15% to be made on the river from the turn. The pot is $100 and our opponents moves all in for his last $20. Should we call?

15% of the time we get $120 and 85% of the time we lose $20:

(.15)(120) + (.85)(-20) = $1

So, calling has an expectation of $1, so we should call. Every time we call, we win $1. Of course, we could win up to $120, which would at the time make us very happy. But really when we make the call we should only be as happy as we would be if we won $1, because the big payoff is lessened by the many times that we don't win and lose a little.

k is that equation true for all forms the basis like this..... (percent to win)(amount of money in the pot)+(percent to lose)(-amount of bet)

is that true in all cases

[Zach6668]

[hijack]

Why is it so difficult for people to converse using the english language? some1, ne1, u, sry, these are not english words. I'm sorry, it just really bothers me, and really taints the credibility of anyone who does that, and thinks they are being serious.

I prefer to converse as adults.

That is all.

Oh, always listen to LLY when it comes to math.

[/hijack]

[Norny21]

[hijack]

Why is it so difficult for people to converse using the english language? some1, ne1, u, sry, these are not english words. I'm sorry, it just really bothers me, and really taints the credibility of anyone who does that, and thinks they are being serious.

I prefer to converse as adults.

That is all.

Oh, always listen to LLY when it comes to math.

[/hijack]

sorry about my english just in a hurry and i do trust LLY with the math but jus seeing if that equation holds true to all hands or just draws or just flush draws

[JMoney2681]

[hijack]

Why is it so difficult for people to converse using the english language? some1, ne1, u, sry, these are not english words. I'm sorry, it just really bothers me, and really taints the credibility of anyone who does that, and thinks they are being serious.

I prefer to converse as adults.

That is all.

Oh, always listen to LLY when it comes to math.

[/hijack]

I dunno what UR trying 2 get so mad 4, some1 is trying to ask if ne1 knows poker stuff, but newayz lets get back on topic k?

[Norny21]

lol i can see his point it is ok i should practice better grammer anyway so is that equation true for all hands even non drawing hands

[LongLiveYorke]

k is that equation true for all forms the basis like this..... (percent to win)(amount of money in the pot)+(percent to lose)(-amount of bet)

is that true in all cases

Basically, yes. If you add:

(percentage of the time that you win)*(amount that you win) - (percentage that you lose)(amount you will lose)

then you will get your EV. The hard part is figuring out your percentage (which is based on your opponent's range) and how much you win (which has to include implied odds).

Also, it gets complicated. Let's say that an opponent could have either a total bluff or a hand that crushes us. We could get into a situation where we either win a little or lose a lot, so we would have to use seperate numbers for how much we win vs how much we lose (reverse implied odds) or we could win different amounts based on many different hands he could have. It's a bit tricky.

[Norny21]

Basically, yes. If you add:

(percentage of the time that you win)*(amount that you win) - (percentage that you lose)(amount you will lose)

then you will get your EV. The hard part is figuring out your percentage (which is based on your opponent's range) and how much you win (which has to include implied odds).

Also, it gets complicated. Let's say that an opponent could have either a total bluff or a hand that crushes us. We could get into a situation where we either win a little or lose a lot, so we would have to use seperate numbers for how much we win vs how much we lose (reverse implied odds) or we could win different amounts based on many different hands he could have. It's a bit tricky.

wow yea ill say so is this the way to play, play the +Ev hands and muck the -Ev hands either way i need to learn math a little bit better

[LongLiveYorke]

wow yea ill say so is this the way to play, play the +Ev hands and muck the -Ev hands either way i need to learn math a little bit better

So, obviously it's impossible to do complicated EV calculations at the table. And it's impossible to every truly know what your EV is expect for very specific scenarios involving all ins and draws that you for some reason know are live.

EV calculations are usually approximations that help you make your decision in a tight spot. Based on pot odds, one can calculate how often they have to be right about a certain decisions (making a call on the river, for instance) for it to be profitable. If you only have to be right 1 time out of 10 for instance (as in you're getting 9 to 1 on the call in pot odds) then you should greatly lean toward calling. It gives you a rough estimate of what type of calls or bets or whatever you should be making.

In a very theoretical sense, the object of poker is to make all +EV decisions. More specifically, it is to make the decision that has the highest EV value. Again, though it's impossible to calculate your exact EV, it is a guideline to follow when thinking about decisions. It is how we should think about poker and poker problems. For instance, we don't make a bluff because we think he will for sure fold, but we make a bluff because in the long fun he will fold enough based on the pot size versus the size of our bluff to maximize our earnings in the hand (versus not bluffing at all, etc). It is a theoretical guideline that dictates how we as poker players think.

[Norny21]

k despite all the math involved i think i got it its jus a small factor of the game like tells, reads, our opponets style, my hand it gos along with that and should be weighed somewhat equally when making a decision, is that even close to being right

[Actuary]

k despite all the math involved i think i got it its jus a small factor of the game like tells, reads, our opponets style, my hand it gos along with that and should be weighed somewhat equally when making a decision, is that even close to being right

:taking baton from LLY:

not really.
EV encompsses everything.
It's not a small part on par with tells/table texture/reads/day-of-week.
All those other elements need to be a part of your "equations" with each move you make such that you maximize your Expected Value. If you "read" Billy as weak, you should think that the Expected Value of bluffing with your Ace high will be higher than bluffing with Ace high when you read Billy as strong

EV just comes as a natural by-product of considering all past/present/future actions/cards/reads/etc in a hand that impact what you can expect to make/lose. You try with each play to maximize your Expected Value, or in a broader sense..with the combination of plays within a given hand or session. Sometimes, you may even make less than optimal plays to raise the EV overall on future plays. For example, making a loose call from the blinds and calling down a small pot with a very marginal hand. This may set up a chance to trap later.

Sometimes that involves taking more risk. You should never play at a level where you sacrifice EV for less risk.

and if it doesn't sink in, don't worry about it.

I never really understood matrices or moment generating functions; but I learned enough to pass test and get a job.