Calculating EV

[James Boston]

I hear EV discussed, and I understand the gist of it, but don't know how to calculate it. I've recently started trying to keep good records of my playing, and want to know how to figure EV. Currently, I just take my hourly earnings and convert that into big bets per hour. Is this completely out of the ballpark?

[CrisBrown]

Hi James,

EV isn't about your expected hourly return. It's about the value of a given hand relative to the pot odds.

E.g.: You hold JTs on a flop of 8-9-3 with two of your suit, giving you both a flush and a straight draw. There is $250 in the pot, and your opponent bets $350. You put him on a pair (for whatever reasons having to do with your hand-reading analysis). You have 19 outs (9 for the flush and 8 for the straight) with two cards to come, which makes it around 1:2 for you to draw out. Your call would be at 10:7 pot odds ($600in the pot for a $350 call), so the call would have "negative EV," i.e.: the pot odds don't justify your call.

The correct decision is to fold ... and even if the next card is a Q, 7, or one of your suit ... you still made the correct decision.

Cris

[Nottom]

[ QUOTE ]
E.g.: You hold JTs on a flop of 8-9-3 with two of your suit, giving you both a flush and a straight draw. There is $250 in the pot, and your opponent bets $350. You put him on a pair (for whatever reasons having to do with your hand-reading analysis). You have 19 outs (9 for the flush and 8 for the straight) with two cards to come, which makes it around 1:2 for you to draw out. Your call would be at 10:7 pot odds ($600in the pot for a $350 call), so the call would have "negative EV," i.e.: the pot odds don't justify your call.

[/ QUOTE ]

If you are folding straight-flush draws with 2 overcards you are making a big -EV mistake. You are often actually a favorite to win by the end of the hand and should be trying to get as much money in the pot as you can on this flop. Against a pair of 9s you could have as many as 21 outs and 2 shots at it. Even against 2 pair you are probably even money here to win by the river.

[bigpooch]

Exactly. EV is simply the fair value for the play in
question and pot odds is something else altogether (to
help a practical player make decisions).

Here are the number of wins for the JhTh for a flop
of 9h 8s 3h versus a number of hands (you were right
about 98 being close to a coin flip!):

99, 88 or 33: 399/990
98: 504/990
AA: 511/990 or 557/990 (no Ah)
KK: 510/990 or 557/990 (no Kh)
QQ: 452/990 or 480/990 (no Qh)
JJ: 537/990
TT: 615/990
Ah 9x: 631/990
As 9s: 652/990
other A9: 682/990
Ah 8h: 349/990
Ah 8other: 631/990
other A8: 683/990

As you can see from the above possibilities, the
Jh Th is often a favorite!

[Bozeman]

Umm, 600:350 is 12:7 and 8+9=17!=19 and str8 + flush only gives you 15 outs (were you counting overcards too?).

[CrisBrown]

Hi Boze,

You're right and I'm too stupid to do simple math today. I should've stayed in bed. *shrugs*

Cris

[dylhead]

To figure out exact odds you can use the new odds calculator at cardplayer.com. Or you can break out your stats book and do it that way. It can get quite tricky to figure out the exact odds if you haven't had any experience with permutations or independent vs. dependent variables.

[Copernicus]

[ QUOTE ]
Exactly. EV is simply the fair value for the play in
question and pot odds is something else altogether (to
help a practical player make decisions).



[/ QUOTE ]

Pot odds is not something altogether different, they are the odds you need for the EV to be exactly 0.

[Louie Landale]

Yup. Show him your hand and raise all in. Or better yet DON'T show him your hand and raise and take it.

- Louie

[Boris]

lol