1/2 PSB needs to work 1/3 to show profit, how?
Join Date: Feb 2015
Posts: 1,388
I don't understand how a 1/2 PSB needs to work 1/3 of the time to be profitable. Let's say I start with $100 and play 3 hands where I raise $15 pre, get one caller and cbet $15 every time. I win the first hand and lose the other two.
My stack: $100+$15-$30-$30=$55
I just lost $45 overall..
I know the concept probably factors doesn't factor in what's already in the pot but what you need to bet to win it.. but you get the idea of what I'm saying.. it looks good on the surface but when your opponents don't call your cbet, you're only winning 1 bet but when you lose, you're losing 2 bets..
Join Date: Feb 2004
Posts: 3,990
Yes you're counting the cost of the initial raise as part of your pot bet.
If you are magically teleported to flop spots and you bet 1/2 pot, that needs to work one out of three times to be break even.
Join Date: Jul 2012
Posts: 16,008
assuming you have 0 equity when called then
In your example, 66.666 % of the time you will lose the $15 and
33.333% of the time you will win the $30 pot.
-.6666*15 +.3333*30 = -10 + 10 = 0
For any size of bet if you want to know how often you need to get folds to directly profit use the equation:
B/(B+P) where B = bet and P = pot
In your example you bet 15 (B=15) and pot was 30 (P=30)
15/(15+30) = 15/45 = .3333
Join Date: Jul 2015
Posts: 367
Usually EV is calculated relative to folding. Folding is considered zero EV. Once you see that, you realize that money put in pre-flop is irrelevant to calculating EV.
If you consider folding to be 0 EV, than it's profitable to bet 1/2 pot, if you get more than 1/3rd folds.
Just because something is +EV, which is equivalent to saying it's profitable, doesn't mean it's okay to do. It just means it's better than mucking your cards.
Unless you're drawing dead with zero percent equity, checking is always +EV. That means you need to be comparing checking and betting to decide which is most profitable.