[han]

I don't know if one can solve this problem single dummy, but I hope you will give it a try.

10xx
AQJ9xxx
A102
x

QJxx
K
8643
AQ8x

The bidding:
p - 1H - 1S - Dbl
2C - 2H - p - 3NT
all pass

West leads the king of diamonds, which shows a strong holding and asks for unblock or count (low is even). You duck and east plays the diamond 5. After some thought west switches to a spade, east wins the king and plays the club 10. Plan the play.

[rhm]

Okay I bite. I presume dummy has only 6 cards in ♥s
Since LHO did not continue ♦ and seems to have at least 4 of them, I will play on the assumption that RHO must have 95 in ♦.
I will play LHO for being 1♠-3♥-4♦-5♣. If LHO has 1♠-2♥-4♦-6♣, play him to hold the ♥T.

Win the ♣A and overtake the ♥K to run ♥.
In the 4 card ending dummy will have ♠103 and ♦A10
In hand you will keep the ♠Q, a ♦, and ♣Qx
LHO is down to only minors and must keep at least 2 cards in ♦. If he keeps only 2♦s, you throw him in with a ♦ for a ♣ return to your queen.
So LHO must keep all three ♦s and come down to the singleton ♣K, in which case you exit with a ♠ and establish
another ♠ trick.

Rainer Herrmann

[pio_magic]

Assuming N has 6 ♥ only, I count 1♦,1♣, 6♥ tricks so I need one more either in spades or elsewhere. Danger in ♠ will be that E can play a club trough again. Maybe E doesn't also have the 9♣ and my 8 would require W to take the next ♣-trick, so I take the A and play ♠ for the one trick I am looking for. Expect E to win and playing the 8 next promotes the ♣-Q to a stopper....

Peter

[helene_t]

let's assume dummy has only six hearts, otherwise it is too easy.

West would probably have continued diamonds if he held ♦9 so West is likely to have started with x-xx-KQJ7-KJ9xxx. x-xxx-KQJ7-KJ9xx is also possible.

I play ♣Q. West wins and probably plays a ♦Q. I win and unblock ♥K. If E started with only two clubs I can take his last club out and play a small spade to the ten. Not sure how to guard against a 5-3 club split.

[Flameous]

Nv mind. I couldn't count either.

[rhm]

pio_magic, on 2011-April-05, 05:56, said:

Assuming N has 6 ♥ only, I count 1♦,1♣, 6♥ tricks so I need one more either in spades or elsewhere. Danger in ♠ will be that E can play a club trough again. Maybe E doesn't also have the 9♣ and my 8 would require W to take the next ♣-trick, so I take the A and play ♠ for the one trick I am looking for. Expect E to win and playing the 8 next promotes the ♣-Q to a stopper....

Peter

Opponents then have 2♣ tricks, 2♠ tricks and a ♦ trick.

Rainer Herrmann

[gnasher]

I'm assuming North is 3631.

West's diamonds should be KQJ9. He wouldn't ask for an unblock from KQJ7 or KQ. If the defence had a heart stop, West would have continued diamonds. Therefore West has something like x xxx KQJ9 KJ9xx or x 10x KQJ9 KJ9xxx

If, however, he has that, then he should just have continued diamonds (he can throw clubs on the hearts).

Hence I play him for x 10x KQJ9 J9xxxx, and take a finesse. If that loses, I still have the chance that he has misdefended with x 10x KQJ9 KJ9xxx - I'll make a spade trick in due course.

I'm confident that this is not the right answer.

[rhm]

helene_t, on 2011-April-05, 06:08, said:

let's assume dummy has only six hearts, otherwise it is too easy.

West would probably have continued diamonds if he held ♦9 so West is likely to have started with x-xx-KQJ7-KJ9xxx. x-xxx-KQJ7-KJ9xx is also possible.

I play ♣Q. West wins and probably plays a ♦Q. I win and unblock ♥K. If E started with only two clubs I can take his last club out and play a small spade to the ten.

RHO wins the ♠T with the ♠A and returns a ♠. Dummy is dead.

Rainer Herrmann

[pio_magic]

rhm, on 2011-April-05, 06:36, said:

Opponents then have 2♣ tricks, 2♠ tricks and a ♦ trick.

Hmmm, right, OTOH we can still make 9 with the 14th card of N...

Peter

[gnasher]

If West can have ♦KQ doubleton, maybe we should play him for that. If he has x xxx KQ KJxxxxx, we should win, cash three hearts, and duck a diamond.

[han]

rhm's first solution was the correct one, I'm impressed Rainer.

[gnasher]

han, on 2011-April-07, 17:14, said:

rhm's first solution was the correct one, I'm impressed Rainer.

I don't understand why LHO with ♦KQJ7 wanted his partner to unblock. Playing these methods, it's normal to lead the queen from that holding, isn't it?

[rhm]

gnasher, on 2011-April-08, 01:48, said:

I don't understand why LHO with ♦KQJ7 wanted his partner to unblock. Playing these methods, it's normal to lead the queen from that holding, isn't it?

I think you misunderstand the method, which is a sensible one. I play a modified version with some partners
What it means is that the king lead shows a strong holding and asks for an unblock if partner has an honor.

So the king shows

KQJx (partner please overtake with the ace if you got it. If you don't I assume declarer has the ace. Since partner gives count you know whether it is safe to continue the suit. In the actual layout the ace was visible in dummy, but opening leader could see that continuing ♦ would develop a trick for declarer)
KQTx (partner please unblock the jack or ace if you got it. If you don't I assume declarer has those cards. Since partner will give count you will know when to drop a doubleton jack, if say the ace is in dummy)
AKJx (partner please unblock the queen if you got it . If you don't I assume declarer has the queen. Since partner gives count you will know when to drop a doubleton queen)

But it would also be led from AKQx or better.

In this method the ace lead never shows such a strong holding.
From KQx you lead the queen or low.

Rainer Herrmann

[han]

gnasher, on 2011-April-08, 01:48, said:

I don't understand why LHO with ♦KQJ7 wanted his partner to unblock. Playing these methods, it's normal to lead the queen from that holding, isn't it?

Perhaps you would. This is the auction and lead that was made at the table by people with these agreements.

[gnasher]

So if I lead the king, dummy has xx, and partner has 10xx or Axx, what is he supposed to play?

[rhm]

gnasher, on 2011-April-08, 05:51, said:

So if I lead the king, dummy has xx, and partner has 10xx or Axx, what is he supposed to play?

That why I say I play the method modified:

In notrump the king promises at least a 4 card suit. Otherwise lead ace or queen, depending on your honor holding.
Unblock with a doubleton and hope, which is fairly normal when partner leads an honor.

For the rest assume you have 3 or more cards when partner leads the king:

If dummy has a doubleton or less, play attitude (not count and do not unblock) So in your example I give attitude.
If dummy has 3 cards unblock. (Rare exception would be if you deem it necessary to get on lead, very rare at notrump, a little bit less rare in a trump contract)
Of course I do not unblock when dummy comes down with Jxx and I hold the ace, partner having led from KQTx(x). Here I give count.
If dummy has more cards inspect whether you and partner will be able to beat them if you unblock, otherwise give count.

Rainer Herrmann

[gnasher]

Well I wouldn't describe it as "asking for an unblock or count" if it actually meant "asking for an unblock or count if dummy has three, and for attitude if dummy has two".