[Apollo81]

RHO opened 2♥ first seat favorable at MPs.

He has:

♠98
♥AQ8752
♦?83
♣J2

The missing card may be the king or jack.

The only relevant thing I can think of from the bidding or play is that this expert player gave a (correct) count signal in diamonds looking at Q1072 on dummy when the 2 was led.

What are the odds that the missing card is the ♦K vs the ♦J?

[Halo]

I guess the modern view is that if you give him the King he is too strong. So we play him for the Jack.

[Apollo81]

Halo, on Jan 19 2007, 04:17 PM, said:

I guess the modern view is that if you give him the King he is too strong.  So we play him for the Jack.

Well, its a conservative opp who is a teammate of mine sometimes. I think he would open 2h with the king .

edit: obviously nothing is 100% here.....how much more likely is he to hold the J than K
I thought about 3:2 at the table

[Echognome]

This is impossible without knowing your customer on the right. I presume this is a play problem where you have to guess the missing diamond. Presumably with the J, you will give false count in case declarer has AKx in diamonds and must guess the suit.

[Apollo81]

Jlall, on Jan 19 2007, 04:34 PM, said:

I don't understand this question. I'll go with the obvious 50/50...he can have either if he would as you say open 2H with the king.

I would always open 2h with either card unless i had agreed to play very destructive preempts at favorable. I dont understand a lot of people who find reasons not to preempt....maybe he would look at xx AQxxxx Kxx Jx and say "too much defense" or "too many flaws" or something

I was asking, since you cant read the guys mind, what are the chances he would fail to preempt if he had the king? I was rejecting the explanation that he would never preempt with the king because of hand strength.

Not a great question anyway. Feel free to ignore me.

[awm]

It depends a bit on the whole hand. Assuming dummy has other entries, it seems like giving false count with the jack is more likely to be effective. If the suit is 4-2 (with weak two bidder having two) then playing to the ten is more likely to be right (picks up KJxx onside). If dummy has no other entries, then it becomes important to convince partner to hold up the king and giving correct count with the jack might be more likely.

Of course, if this player is a real expert and knows that declarer is a good player he may realize that declarer has a complete count regardless, in which case he would always give accurate count (to help partner if needed) and it's a complete 50-50 tossup (assuming he wouldn't open 1♥ with the diamond king, which a lot of forum regulars seemingly would).

[inquiry]

50/50... even with the Diamond king, only 25 Zars. I would open 2♥ (well 2♦ multi if allowed).

give me one less spade and one more minor card then with the king of diamonds, I would probably open 1♥...

[cherdano]

Of course I can't give you the answer. But if you think the opponent would always open 2♥, and give correct count, say, 70% of the time when he has the J but 90% of the time when he has the king, the odds would now be 56% for the K and 44% for the Jack.

How do you compute this? The odds of having the king is 50%, so the odds of having the king AND giving correct count is 45%. The odds of having the Jack and giving correct counts is 35%. So the odds of giving correct count are 80%. Now that you know he gave correct count, you have to throw out the 20% where he would give incorrect count, so the odds for having the king, knowing he gave correct count are 45/80 = 56.25%.

Arend

[pclayton]

I'd put a lot more faith into any tell I got from LHO than trying to calculate the specific odds.