[Yzerman]

Here is a very neat defensive problem that occured in a sectional about a year ago. I really wish I could post these as two separate topics because it requires both defenders to make nice plays.

MP
N/S Vul
Dlr S

Your hand is the bottom hand and the dummy is shown on your right.  You are vul, opps are not.

Auction

N.....E.....S......W
..............1H....2D
2S...4D...4H....5D
X (all pass)

..............xx
..............xx
..............xxxx
..............KQ10xx

Kx
AKxxxxx
Jx
xx

Partner leads a middle heart.  Plan the defense!

[inquiry]

Fun to see a matchpoint problem being posted.  For the uninitiated to matchpoint strategy, on this hand beating 5D only three (down 500) or less will be a horrible result since 4Hs vul sure looks like it was making (+620 or better). Thus, you need to  find a line of play that allows you to take 6 tricks.

For your partners forcing 2S bid and the opening lead, surely you will score two spades, two hearts and a club (I am assuming the middle heart lead shows partner with either a singleton or two small, for with QJx he would lead Q, and with Qxx or Jxx he wouldn't lead the "middle" one) and partner needs two aces to scap together a forcing 2SPADE bid.

But even with two aces, partner is light for his 2S bid. If he was 5-5 in the black suits, we think partner would have made a negative double. If partner is 6-2-1-4 with both black aces, we can score our Diamond jack by overruffing dummy on the third round of spades if we carefully cash both hearts before three rounds of spades. But we need to protect against partner being 7-2-1-3 and 7-1-1-4.

So with partner being 7-2-1-3, West is 2-2-6-3 or 2-3-6-2 (if partner is 7-1-1-4). The question is where is that 6th trick coming from? The answer is a trump promotion, requiring partner to have singleton DIAMOND Q or K if WEST has two hearts, or the singleton DIAMOND K, Q, or T if WEST has three hearts. The straight foward play is to cash a second heart immediately (I take heart ACE first then heart KING) to illustrate to partner that I have an idea on this hand. For him to spend a few seconds thinking. If parnter follows to both, or shows out, I lead a low spade (see below).

The thought here is that partner will know be able to work the hand out. I don't have a singleton club, or I lead one earlier. I don't have club void, or I win HEART ACE (denying king rather than immediately showing it) and lead a spade to get a club back. So he will should work out that I want to cash two spades before continuing the third round of hearts. Now partner will look into his hand. IF his biggest diamond is not bigger than the 9 in the dummy, he knows my ruffing strategy will not work. Thus, if he has only six spades, he will win this spade cheaply, cash the club and spade ACES, then lead a spade for an attempt for me to score my trump JACK. Thus partner with 6 only spades without a trump higher than the 9, will find my spade ruff after all. But with the diamond TEN (singleton Heart) or Diamond Queen (doubleton heart), he should find the low spade back to my hand (maybe after cashing club ACE), so I can then exit a heart for my trump promotion.

This defense should work if partner has 6S, or 7S and 2 hearts with a singleton K or Q of Diamonds, or 7S-1H-1D with the one diamond being the K, Q or T

The position you have to play for is something like the following....
       North  
       AJxxxxx
       xx
       Q
       Axx

Qx         xx
QJ         xx
AKT32      xxxx
Jxx        KQTxx

       Kx
       AKxxxx
       jx
       xx  

[Yzerman]

Well in a few million words you worked out the solution.  There are only a few hands that you CAN come up with 800 and you described the two of them.  So you just need to find a defense that caters to both.
Indeed partners hand was;

AQxxxxx  x  Qx  Axx

The key is;

a) You cant uppercut from your side when p has stiff Q
You cant promote from his side when p has stiff Q

Doubleton Q is not a problem, only stiff Q and Bens defense as described catered to both stiff Q and double Q.  On this hand you could have cashed hearts then play spades and hope to overruff dummy but this does not work when partner has 7 spades and stiff Q.

As challenging a problem this is from your perspective, imagine the pressure (and the anxiety from not getting his immediate H ruff) that partner is feeling!