need some help with a odds thing

[deviouz]

I read an old poker book about nl hold'em, and I found something interesting, the thing is, I have been trying to convert to nl for quite some time and this is new to me, I know how to calculate pot odds, but this I dont know how to calculate and is what I need help with, the situation the author writes about is this, you are in a satellite tourny trying to win a seat to the wsop, you are on the final table with only three other players remaining, the blinds has just gone up to 200/400, you have 1900 chips and are now required to use 400 to post the big blind, leaving you with 1500, your hand is KQ offsuit, the player on your immediate left opens with an allin bet of 1950, the other 2 players fold and it's up to you, you think the raiser has ace rag or an under pair, do you call or fold? the author explains why you should call, or why a call would be correct mathematically,
you are getting 2500 to 1500 in pot odds wich is 5 to 3 he writes,this means you need to win 37,5% to be making the right play mathematically since a KQ is 42% against ace rag and 38% against ace rag suited, and against an under pair you are close to even money, now to the part I need help with, he writes Im getting 2500 to 1500 in pot odds, that I understand, and he writes that it's 5 to 3, this I don't understand, I thought it was 1,67 to 1, I never seen 5 to 3? I have seen 5 to 1, 4 to 1, and even 3 to 1 but not to 3? how is this supposed to be calculated? and how does he calculate I need to win 37,5% to make in profitable?

[AaronBrown]

5 to 3 is the same as 1.67 to 1, just divide both sides by 3. Before the days when everyone had calculators, it was easier to state everything in integer ratios, like 5 to 3. With calculators, stating everything "to 1" means you only have to transmit one number instead of 2. But don't let the difference fool you.

Getting A to B pot odds means there are A dollars in the pot for every B dollars you need to call. So this is 2,500 to 1,500; or 25 to 15; or 5 to 3; or 1.67 to 1; or 1 to 0.6. All those mean the same thing.

The nice thing about 5 to 3 is it makes the required odds calculation easy. Imagine that you play 5+3 = 8 hands. If you lose 5 and win 3 you will break even. Why? You lose $1,500 5 times, for a loss of $7,500. You win $2,500 3 times, for a gain of $7,500. So you need to win 3 out of 8, or 37.5%.

In general, with A to B pot odds, you need to win B/(A + B) to break even. 1,500 / (2,500 + 1,500) = 15 / (25 + 15) = 3 / (5 + 3) = 1 / (1.67 + 1) = 0.6 / (1 + 0.6) = 0.375.

By the way, your stack is small enough relative to the blinds, and there are few enough other players, that you start thinking about tournament position rather than just expected value. KQo is a pretty good hand for getting a chance to double your stack and eliminate the fourth place player. If you fold here, you may get a run of unplayable cards and end up going all-in with J4o and $1,300 in chips; or worse.

[deviouz]

I thank you for that ansver, but lets say I want to use that example you just wrote to find out if my hand qualify for a call, we can make an ex, the blinds are 250/500 I got 4000 and I got the same hand as previous, I post 500 in the BB that leaves me with 3500 and the same guy set me all-in with 2000, then I have the pot odds 3250 to 2000 1,63 to 1, how do I convert that to the 5 to 3 ratio abowe? or more important how do I get the procentage to brake even or find out what hands I can call with?, should I multiply both sides by three then?

[AaronBrown]

Let me make sure I have it right. There's $750 in the pot from the blinds. You posted $500 of that in big blind. One player (not the small blind) goes all-in for $2,500. Everyone else folds. So when it gets to you there's $3,250 in the pot, and it's $2,000 to call. Since your stack is greater than $2,000, it doesn't matter to the problem.

Your pot odds are $3,250 to $2,000. You can divide both sides by 250 to get 13 to 8, or you can leave it as 3,250 to 2,000 or go to 1.625 to 1 or whatever you want. Regardless, you break even if your chance of winning is 8/21 or better (or 2,000/5,250 or 1/2.625; it's all the same number). 8/21 is about 38%.

The only hands that have large negative expectation for you are AA and KK. You're close to break-even against QQ or Ax, and you have some positive expectation against other likely all-in hands. But he has to be wild enough to go all in with hands like KJo or JTs for you to be the actual favorite in the hand.

Against a loose player, of course, you call for the +EV. Against a typical tight player it's probably close to zero EV, but you'd generally rather call. After all, if she's tight it's breakeven but if you're mistaken about that it's positive EV. I would generally fold this against players who go all-in only with the strongest hands (which doesn't necessarily mean they're tight in general). Of course, the personalities, skill level and table situation matter as well. With a bad player at an easy table, you might fold and figure to get the money back in a more favorable situation later.

[deviouz]

thank you very much! this was very helpful