Disclamer: this is rather a long post as I wanted to include all my thoughts on the subject so people responding would be able to be specific if they were to correct me, also, I do appreciate anyone willing to read through this and give feedback
BTN: 101.4 BB
Hero (SB): 173.2 BB
BB: 217 BB
UTG: 119.4 BB
CO: 161.4 BB
Hero posts SB 0.4 BB, BB posts BB 1 BB
Pre Flop: (pot: 1.4 BB) Hero has A
T
fold,
fold,
fold,
Hero raises to 3 BB, BB calls 2 BB
Flop: (6 BB, 2 players) 4
5
Q
Hero bets 3.2 BB
How can we calculate EV for this flop bet?
preflop BB calls with 307 combos
on the flop villain has 278 cmbs, versus hero's flop bet villain will continue with 197 combos and this range has 52% equity vs Hero's holding
197/278=0.71 thus villain continues 71% of the time and fold 29% of his starting range on the flop
Now, betting 3.2bb into 6bb pot hero needs 35% folds for a play to be break even
risk/risk+reward
3.2/6+3.2=0.35
villain doesn't fold enough so bet itself is -EV
We can calculate EV of this bet:
times villain folds * pot - times villain continues * Hero's bet
0.29*6-0.71*3.2=-0.53bb
but this calculation is only true for pure bluffs as we assume that when villain continues Hero will always lose, in the example above hero has 48% equity versus a range villain would continue with
Yes, villain can deny us realizing our equity through raiseing and/or betting on other streets, his further actions can effect (or are effecting) his range, turn and river cards will change our equity, but do we care about all that when we are calculating EV of a singular action on a given street? all we need is villain's continuationg range and percentage of times he'd fold, and from that we get the EV of a play, realizing our equity after the play does not depend on a play we are calculating for
But then how do we calculate the EV of that bet?
times villain folds * pot + times villain calls * (hero's equity * pot) - times villain calls * (villain's equity * hero's bet)
0.29*6bb+0.71*(0.48*6bb)-0.71*(0.52*3.2bb)=+5.69bb
as in case we had 0% equity (a pure bluff) the formula would look like this:
0.29*6bb+0.71*(0*6bb)-0.71*(1*3.2bb)=-0.53bb
same as 0.29*6-0.71*3.2=-0.53bb
========================
MP: 115.6 BB
CO: 73.2 BB
BTN: 100 BB
SB: 117 BB
Hero (BB): 100 BB
UTG: 136 BB
SB posts SB 0.4 BB,
Hero posts BB 1 BB
Pre Flop: (pot: 1.4 BB) Hero has 5
K
fold,
fold,
CO raises to 2 BB,
fold,
fold,
Hero calls 1 BB
Flop: (4.4 BB, 2 players) 6
9
5
Hero checks,
CO bets 2.2 BB,
Hero calls 2.2 BB
How do we calculate EV for Hero's call on the flop?
villain opens CO with 333 combos
on the flop he has 307 combos
he bets 2.2bb into 4.4bb pot
his betting range has 170 combos and has 60% equity versus hero's holding
Hero would be calling 2.2bb to win 6.6bb
risk/risk+reward
2.2/2.2+6.6=2.2/8.8=1/4=25%
so we need 25% equity to have 0 EV
0.25*6.6bb-0.75*2.2bb=+0bb
but we have 40% equity versus villain's betting range, therefore:
0.4*6.6bb-0.6*2.2bb=+1.32bb
so is it fair to say that this flop call brings us +1.32bb?
also, if hero would raise here to 6.6bb and villain would continue with 40% of his betting range having 84% equity when he continues we'd have the next scenario:
hero is risking 6.6bb to win 6.6bb
risk/risk+reward=6.6/6.6+6.6=1/2=50%
thus this raise is +EV
how much +EV?
times villain folds * pot + times villain calls * (hero's equity * pot) - times villain calls * (villain's equity * hero's raise)
0.6*6.6bb+0.4*(0*6.6bb)-0.4*(1*6.6bb)=+1.32bb
so if hero had 0% equity when villain continues hero'd make 1.32bb on this raise, but he has 16% equity, thus:
0.6*6.6bb+0.4*(0.16*6.6bb)-0.4*(0.84*6.6bb)=+2.16bb
Therefore, if hero's estimations are correct raise to 6.6bb in this spot will bring 0.84bb more then a call, thus if we'd have only these two options raise is an optimal play
Also, all that should mean that when we are bluffing with a hand that has some equity versus villain's continuation range we need less folds to break even on a play
If all EV calculations above are correct, I can safely assume that I can solve any spot accurately: call, bet, raise, and I guess check would just realize EV you already have considering your holding and villain's range and fold is always 0 EV
Also, in all the examples above I was useing Equilab hand vs range calculations, I assume if I'd use range vs range calculations nothing (except the percentages) would change