Calculating EV from preflop
Hi guys,
I'm pretty new to the field of online poker playing and have been reading much on the subject (Kc's posts are, well, like warm robitussin. Unpleasant to take in but quite helpful). What is leaving me with a huge question mark though is calculating EV adequately from the preflop perspecive.
Most articles online that gives examples on how to calculate EV gives examples from the flop. Let me state an example I've found on the web for you so you understand better what I mean.
"You have 5♠ 6♠ and the board is 7♠ 8♠ A♣. Your opponent accidentally flips over his hand as he bets $10 into a $60 pot.
He has A♥ K♦. He has top pair aces with the best kicker.
You have a straight draw and a flush draw. You can only win if a spade falls or if a 9 or a 4 comes.
There are nine spades left in the deck plus three nonspade fours and three nonspade nines.
That makes a total of 15 outs.
You have seen 7 of the 52 cards in the deck leaving 45 remaining, meaning 15/45 cards win it for you.
The odds against you hitting your hand are 21. The pot odds are laying you 71 as you have to call $10 to win a $70 pot.
This bet is extremely +EV. On average you will win double your investment."
In an example like this one there are so many annoying unkowns that I feel the maths are not right. First we don't know how many players are at the table or how many are in to see the flop. So this makes it very hard to get a feel of the initial required investment from the players to make it a 60$ pot preflop. If there are 6 10$ betters preflop to make it to 60$ then we need to factor in that there was an initial 10$ investment to the real gain from the get go is a potential of 50$ and not 60$. If it's heads up it's even worse, both players had to be blinds and regardless, they both have commited 30$ to the pot preflop which makes the potential winnings 30$ and not 60$. In a situation like this it would be ludicrous to go 30$ deep (thus purchasing 50% of the pot with very low equity) in a heads up with a suited connector of rags considering you'll lose most of the time.
So here it is, calculating EV from the flop as stated in all the examples I've found all over the place is very easily understandable and easy to calculate/predict. But where I'm a little at a loss is factoring in the required inverstment from the beginning of the hand because this has to drastically change EV for a lot of hands. Or am I getting it wrong?
Thanks for reading and happy betting!
LeLedg
Last edited by LeLedg; Sep 22, 2012 at 2:23am.
