
17.01.2014, 12:05

0

This post has been edited 1 time(s), it was last edited by Kyyberi: 04.06.2014 17:05.
There are two different ways to play in position preflop. One is to open with a wide range from BTN/CO and one is to open with stronger range. I made a little math to find out how it really is.
The Myth:
In PLO25 Zoom, folding equity preflop (from BTN against the blinds) is so low that one shouldn't open trashy hands.
Lets assume that the Myth is right. Of course we open any4 against nits, but against unknown players we open only for hand strength value. We are not facing a lot of 3bets from the blinds, so we don't have to adjust our betsizing against that. So we should open full pot to get the maximum value. Here is why:
When we open with strong range, we will often hit stronger than our opponent. And with good hands, we will hit more than we miss. When we compare 2bb and 3,5bb raises preflop to the amount we will win postflop when we cbet 3/4 pot otf, ott and otr, it looks like this:
Pot Pre  Flop  Turn  River (our value)
4  10  25  62,5 (31)
7  17,5  43,75  109,4 (55)
So that small difference preflop is quite big postflop.
BUT!!! Is the myth right?
I looked at my database and found out that when it comes to BTN unopened, and hero opens, blinds actually fold 50% of the times on average. When hero gets called, half a pot cbet is succesfull 40% of the times. Lets analyze a situation where hero doesn't even look his cards, but plays stab and fold poker (raises pre, SB folds and BB calls, makes a half a pot cbet and gives up if called/raised).
Raise 3,5bb = preflop we risk 3,5bb to win 1,5bb. To be breakeven we need 70% FE. We have only 50% so we lose 1bb in EV. OTF we cbet 3,75bb to a pot of 7,5bb. We need 33% FE to breakeven, so our EV is +0,75bb. So our total EV is 0,13bb.
Raise 2,5bb = preflop we risk 2,5bb to win 1,5bb. To be breakeven we need 63% FE. We have only 50% so we lose 0,5bb in EV. OTF we cbet 2,75bb to a pot of 5,5bb. We need 33% FE to breakeven, so our EV is +0,75bb. So our total EV is +0,13bb.
So if hero doesn't even look his cards and makes cbet always against one opponent, the other is EV and the other is +EV.
Results: if you open with a wide range from the BTN, it's better to open 2,5bb than 3,5bb. If you open with valuerange, you should open 3,5bb.
Note: these are just the vacuum lines against unknown opponents.
edited post with precise calculations 4.6.2014