# The need of calculating EV?

I need to clear something myself on EV topic. I know that EV calculation is:

``````EV = (Percentage of hit * Pot size) + -(Percentage of not hit * Call size)
``````

I might be wrong but isn't the following a bit easier?

``````A = (percentage to hit * Pot size)
B = (percentage to lose * Call size)
If A bigger, call
``````

I mean, who cares of the exact amount of EV? just + or -, or is there a meaning of how much you're losing in the long term if you just losing at all?

PS.

In cases of, lets say, a flush draw i mostly count pot odds. When i have, say 150 in pot and the amount to call is 50, pot odds are 25% (200 to win and 50 to call) and my hand odds are 20% (flush draw). It tells me also to not call (pot odds are bigger) so this is also true but somewhat easier than both ways of EV calculation. Are there any cases where EV will get us something different / hidden than pot odds calculation? I'm speaking of cases where the math can be completed in less than 15 seconds of a typical online cash game street :)

So, my questions:

• Is EV calculation needed when pot / hands odds are known?
• Any ridiculous error on my EV logic above?

tx

• The context might force you to fold, even if a call is CLEARLY +EV. Think of the bubble, for example. Or securing an extra \$3000 because there's a super short stack at the table. In these cases, how big the plus or the minus is might be relevant. – Radu Murzea Nov 8 '13 at 15:35
• Thanx but i dont know much about tournaments, i'm playing only 6-max online cash games. I know what are you talking about though, the slightest details can turn your tournament position for the better. But in my easier EV above isn't that enough to just know that A & B are "similar" and close to blinds, like -10 loss (if etc. BB is say 5) could mean "ok, lets call" and -40 means "nope". It would make any difference if i calc pot-odds and EV to cross-eval on a situation or they're different and EV more post-analysis stuff? – user1165 Nov 8 '13 at 17:39
• I find your calculation unintuitive but that's almost certainly due to my personal methodology. Check this Q out: poker.stackexchange.com/q/78/88 – Toby Booth Nov 9 '13 at 1:09

Direct EV calculations are the first step in figuring out how to calculate "maximized EV" based on situational considerations. To become a better player, you will very much care about the size of your positive EV.

Sure, the basic EV calculations say to either bet, call or fold based on card odds vs pot odds. Usually, you're only really looking for a positive or a negative EV. However, when you start playing against better players, you need to work on maximizing your EV to get the most value of a particular situation. This gets into implied odds and equity.

Here is a link to a good article on the subject:

Cards Chat: Expected Value & Poker Explained

In certain situations, your expected value may change or be maximized if you check-raise, or you lead out on the flop with second pair or just air (making your crappy hand look better than it is, thus altering your opponents calculation), or calling a bet on the flop where you can make it look like you hit a straight or flush on a later street, or betting on the come for a flush or straight. However, where these are advanced plays, to get the correct EV, you need to put your opponent on a hand AND guess what they will do in a particular situation. A classic EV maximizer is the slow-play of the flopped set when you know you have an aggressive player to your left. Simple EV would have you bet out rather than slow play.

You might notice that some of these situations would potentially give you a positive EV even though your cards have you drawing dead. Then your playing real poker, my friend. Just don't do this with idiots or beginners, as the great Doyle Brunson sagely put in Super System I: "you can't bluff an idiot."

Just pulling these poker plays is not interesting unless they are done in the context of a situation and possible outcomes based on a psychological profile of your opponent. Then you can get the the next level of EV. The math is a little obtuse and I can't imagine someone really doing the EV math for situational poker on the fly in their heads, but you could understand the EV impact of various plays, such as the tried-and-true check-raise, and apply it in the correct situation to get a boost in your overall EV.

Also, "maximized EV" plays go both ways with poker players. This is what the top players mean when they talk about the "mental warfare" that goes on in big tournaments and big cash games. While you are working our your EV maximization strategy, your opponents, if they are good, are working out theirs. You have to incorporate what you think they are thinking and what they think your are thinking into your EV calculations. Some guys are just natually good at this. That is poker talent, IMHO.

The idea behind poker, especially tournament poker, is to maximize your win when the opportunity presents itself. Simple EV can "leave money on the table" so to speak. If you can maximize your EV you'll, over time, simply win more money/chip is a shorter period of time. And money/chips over time is how we keep score in poker.

• +1 I really like how you explained things ;) . I would give you another +1 for quoting Super System, but I can't :( – Radu Murzea Dec 9 '13 at 14:41
• very good explanation, so EV amount indeed matters, some articles forget to refer such details, leading to hilarious questions as mine :) Tx – user1165 Jan 2 '14 at 2:49

It may look easier to you but it's just a mental (mathematical) trick, in fact you're basically stating the same thing:

Consider it like this.

To call:

``````EV > 0
A = (percentage to hit * Pot size)
B = (percentage to not hit * Call size)
``````

EV = (Percentage of hit * Pot size) + -(Percentage of not hit * Call size)

So:

``````EV = A - B
``````

And with `EV > 0`

``````A - B > 0
``````

so

``````A > B
``````

In addition, while EV is fine... you're forgetting to take into account implicit odds.

• Hi, yes i know i'm stating the same thing :) but stripping off the winning / losing amount, thus making it easier and a less than 15 secs of thought as i stated above. But i know now the EV is not for on-the-fly sessions and stripping off amounts, as i did, is not of use. Pot odds are for this kind of work. Implied odds? They're quite abstractive to be taken into any formula, aren't they? I'm just modifying my pot odds when i am taking account implied ones (etc. i just add some guess amount). Is there any hidden connection between EV and implied odds im forgetting about in EV formula? tx – user1165 Nov 23 '13 at 2:35