Originally Posted by baztanen
Hi, please help me reconcile these ideas.
I've been taught that when looking at EV of different actions, that we should view the EV of folding as zero "by definition".
I'm a bit confused though because there are times where because of the dead money, we should be making an "losing" play that is still better than folding.
An example of this might occur when in the big blind. There are certain hands where if you were to play them, you might have a -50bb/100 "win rate" (loss rate) in your holdem' manager, however if you were to fold that hand every time, hold'em manager would show -100bb/100...so in this case, we are not comparing our EV to zero, but we're comparing our EV to -100bb/100 and since -50bb/100 is a better loss rate than -100bb/100, we should still play the hand.
You are having a baseline problem. EV is always calculated relative to some baseline stack size, say Sb. Then EV = expected stack size after the hand – Sb.
Usually, the baseline is your stack size just before a decision is made. In that case, if you fold, your stack size after the fold is exactly what it was before you folded. That is why they say that for a cash game, EVfold = 0. But then the EV of a call or raise decision has to use the same baseline.
Your hold’em manager evaluations use as a baseline your stack size at the beginning of the hand. For argument’s sake, assume it is 10bb. HEM gives a win rate of -100bb/100 meaning an EV of -1bb for one hand if you fold as the big blind. That is your loss when the baseline is your stack size at the start of the hand. So, HEM says that if you fold, your stack size will be 10-1= 9bb, which of course is correct.
To make discussion a bit easier, assume hold’em manager has a -60bb/100 loss rate with betting. That is equivalent to having 0.6 bb less after the hand plays out, on average – you started out with 10 bb and now have 10-0.6 =9.4 bb. Since 9.4 bb is better than 9 bb, a bet is better than a fold.
Now, let's use our stack size just before betting as the baseline, which would be 9 after posting the blind? Clearly, our stack size doesn’t change with a fold, so it remains at 9; therefore EVfold = 9-9 = 0bb in this case. And, with a bet, HEM tells us that we have 9.4bb. So, EVbet is 9.4 – 9 = 0.4bb, which confirms that betting is better than folding.