Tricky spot on an action flop with ~250bb vs a LAG

[benwood]

Shoot while you've still got the gun. C/R his arse.

[jhall23]

[ QUOTE ]

Ok, suppose your opponent has a hand like A876, then if he doesn’t improve on the turn, calling on the flop and betting the turn when a rag comes will have the same effect as check-raising the flop. So, you have gained nothing there.

But supposing he makes 2 pair on the turn (e.g. if he has A876 and a 6 comes on the turn), then you’re a 37.5% underdog. If you bet the turn then he should raise all in and at that stage you have to call.

So, assuming your opponent has A876, let us compare the EVs from the point where he bets the flop.
If you check-raise, he should fold, giving you an Ev of $23.40 (I’m not saying he will fold but just for just for the sake of argument and ease of calculation, let’s say he does).
However if you call the flop bet, then bet the turn and are raised all-in, you have risked $57.40 to make a profit of $69.10, and at this stage your are a 37.5% underdog so this is a –EV play
(about -$10 if my calculations are right).
So you have gone from a +EV of $23.40 to a –EV of $10, and this is why I think this play is very bad.
I’m a bit rusty on the EV calculations so you might want to check them.
All comments appreciated.

[/ QUOTE ]

Not sure how you calculated the EV of the second scenario there. Was it simply I am risking 57.4 and my 37.5% equity in a ~125 pot is 46.8 for a difference of -10.5?

If so I agree with that calculation, but that is not the actual EV for check/calling the flop. The -10.5 is the ev of only the situation where he flops his two pair which only happens a small percentage of the time.

I'm no EV calculating wiz, but thinking about it logically to calculate the EV from the flop decision given your assumptions would result in 4 scenarios which you would need to take into account to get the actual EV.

1. Board pairs (A,J or 9 -> 20% )
2. Board doesn't pair and doesn't hit villians hand (~60%)
3. Board doesn't pair and makes villian two pair and I miss (7,6 ~13%) I think this is what you calculated.
4. I make a straight and villian makes 2 pair (8 ~7%).

I'll keep it simple and say that villian will fold if an 8 falls fearing the straight and he'll be gutsy and bet out on any pairing board whether it helps him or not so I will check/fold all pairing turns. So I think the EV would be as follows.

approx. (.2 * -11.7) + (.67 * 23.4) + (.13 * -10)
-2.34 + 15.68 - 1.3 = 12.04

So assuming this is correct given our assumptions then it is still +EV but not as much. If you added in the 4th scenario where I make my hand with an 8 and he makes two-pair and we still get all in then my EV would go up. And if he would check behind on some of the pairing boards my EV will increase (can hit the killer Qc).

But all in all this is something that is very difficult to calculate from the flop decision point because of the range of hands he could have and trying to guess the possible actions. Just on our one hand I am not really sure how likely villian would be to raise with Top and Bottom two on that dangerous board, so realistically I think he folds some % of the time there and he may even call some percent of the time.

Regardless doing that calculation was somewhat usefull for me.

[45Player]

You seem to be missing my point.
In my first post I stated

[ QUOTE ]
Also by just calling on the flop, you’re effectively giving these ‘weaker’ hands a free card, and that is a very bad thing if this free cards improves his hand to the point where he now proceeds to take all your money when he would have folded to a check-raise on the flop.


[/ QUOTE ]

An example of this is the scenario we’re currently discussing where your opponent has just one pair on the flop and he improves to 2 pair on the turn.

You calculated the EV of calling on the flop, plus the action after all possible turn cards, given that your opponent has A876.
That is not what I was referring to.
Clearly if your opponent has a weak hand like A876, and you bet if the turn is a rag, then you don’t need to be a rocket scientist to figure that most of the time he won’t improve and betting out is clearly a +EV play.
Your case 2 above (Board doesn't pair and doesn't hit villain’s hand) happens 60% of the time and this is the factor contributing to the +EV in your calculations. I am ignoring this, as irrespective of whether you call the flop or check-raise, your opponent’s action will be the same. And there is no EV difference between the 2 plays.
I am trying to show where your opponent’s action on the turn (if you call on the flop) results in a different EV than if you check-raise.

I was comparing the EV of
(i) calling the flop with the intention of betting the turn when a rag comes, and it makes your opponent 2 pair,
against
(ii) check-raising the flop.

As you pointed out it’s not going to happen very often. My hand example wasn’t the best to illustrate my point. If your opponent has say, A765 then he has 9 cards to improve to 2 pair on the turn which will happen 22% of the time.
So, in this situation, you have gone for a +EV of $23.40 to a -EV of $10.

As I have said, this will happen infrequently but it may happen.
And when it does happen, then you have made a bad mistake by not check-raising the flop.

EV calculations are all very well but it’s important to interpret the results correctly.
I’m not disagreeing with your calculations – we’re just talking about 2 different things. If you still disagree with me, then we’ll just agree to disagree.

Regards

45

[jhall23]

Edit: woops to double post.

[jhall23]

After your second reply I am definetly on the same page understanding what you are talking about.

Personally, I am more interested in knowing the total EV of check/calling the flop compared to just the EV of when the villian makes two pair. I don't see the value for me to compare the EV of something that happens 100% of the time (c/r'ing and him folding) to the EV of something that happens less frequently. It doesn't give me a good idea of the whole picture of what check/calling then does.

It does put some perspective on why if we take those assumptions (he folds to check/raise and pushes on the turn with two-pair) that it is better for me to check/raise. Good stuff to get me thinking about the situation.

Thanks for the detailed replies [img]/images/graemlins/grin.gif[/img]