In a semi-final match in the Senior trials, you must find the best game opposite partner's weak NT opening.
E-W vul, South deals. As North, you hold:
You play 2-way Stayman opposite a weak NT, so you could bid 2♦ which is game-forcing Stayman. After that, you will be able to ascertain partner's exact distribution or close to it if you so choose depending upon his response.
You could simply bid 3NT, which is probably where you belong. This has the advantage of telling the opponents nothing about your partner's hand, which could make a difference on the opening lead and defense. On the other hand, you would like to get to the best contract. If partner has a 5-card major, you probably belong in 4 of the major rather than 3NT. Also, if partner has a doubleton club you figure to be better off in 5♦ or some 4-3 major-suit fit than 3NT.
Is the concealment factor worth risking getting to the wrong game? This is a matter of philosophy more than anything else. If your hand were a bit weaker, then the opening lead and subsequent defense would be more likely to make a difference. With this much strength if you get to the best game you will probably make even if you tell the opponents all about partner's hand.
You bid 2♦. The bidding continues:
2♦: Game-forcing Stayman
If partner has both majors, he would bid his stronger major first.
If you wish to find out partner's exact shape or close to it, your bid is 2NT. Otherwise, your calls are natural.
Showing the diamond suit doesn't make much sense. It looks better to make the shape-asking 2NT call. Partner will bid naturally. With 5 hearts, he will rebid 3H. Otherwise, he will show a second suit if he has one.
You bid 2NT. The bidding continues:
2NT: Asks rest of shape
3♦: 4+ diamonds
If you wish to probe further, you may bid 3♥ to ask. Partner will bid 3♠ if he has 4 diamonds, 3NT if he has 5 diamonds. If partner is 4-4 in the red suits, you will not be able to determine which black suit is his doubleton.
You would like to know if partner has a doubleton club. If he does, then you probably belong in 4♥ or 5♦ rather than 3NT. But if his shape is 2-4-4-3, then 3NT figures to be best.
Unfortunately, the space limitations are such that you cannot determine whether partner has a doubleton club if he has 4 diamonds. But you can find out for sure that he has a doubleton club if he happens to have 5 diamonds. Your best bet looks to be to continue asking with 3♥. If partner shows 4 diamonds, you take your chances in 3NT. But if partner shows 5 diamonds, you stay out of 3NT -- probably choosing to play 5♦.
You choose to bid 3NT, ending the auction.
Over you go to partner's side to play it.
West leads the ♣6. Standard leads and carding.
What do you play from dummy at trick 1? If you choose to play small and East plays the jack or the queen, will you win or duck?
If the diamonds come in for 4 tricks you have 9 sure winners. You must assume the diamonds lie unfavorably and plan your play on that assumption. The main danger is East having KJx of diamonds.
The club lead is likely to be from a 5-card suit. Suppose you win the ace of clubs and play a diamond to the ace and a diamond up, getting the bad news that East started with KJx. East will win and return a club, which you will be forced to duck. West will win, and put a high spade through you. You will be forced to take the finesse now, since going up ace and playing a diamond would be fatal if the king of spades is onside. If the finesse loses, the opponents can establish their spades before the other diamond is knocked out and you will be down.
Suppose you duck the club. This will be great if West has the QJ. What if East produces one of the honors? If you win, you are in potential jeopardy. If East has the feared KJx of diamonds and 3 clubs, he will knock out the ace of clubs the first time he is in and then run the clubs.
Alternatively, you could duck the first trick. The danger is that East will shift to spades. If the diamonds are bad the opponents will be able to take 2 diamonds, 2 spades, and 1 club, and you will go down even when the king of spades is onside.
Will East find the spade shift? Realistically, that isn't going to happen. If his queen or jack of clubs wins, from his point of view his partner may have the other honors. He will continue clubs. He will be looking at potentially a sure set if he holds KJx of diamonds.
You play a small club from dummy. East plays the jack, and as planned you duck. East returns the ♣9. West plays the ♣3, and you win dummy's ace. What next?
Clearly you will go after diamonds. It appears that the clubs are 5-3. This means that East is more likely to have diamond length if the diamonds aren't 2-2. If you knew for sure that East had at least 2 diamonds, you could lead the queen of diamonds off dummy. This would lose if West has the singleton king (you wouldn't be taking a second finesse into the danger hand), but would gain if East has KJ2 or KJ92. However, even though West appears to have the club length it is still quite possible for him to have KJx of diamonds. If he has this and you don't play ace and a diamond, you will have gone down in a cold contract. But if you play ace and a diamond and East has KJx, you can still survive if the king of spades is onside or you are able to get a third heart trick. This straightforward play looks best.
You lead a diamond to your ace, East plaing the ♦2 and West the ♦9. When you lead another diamond, West discards the ♣4. Your queen loses to East's king. East returns the ♠3 to West's ♠9 and dummy's queen. You lead a diamond, and East wins his jack. Do you unblock the ♦10?
It looks instinctive to unblock the ♦10. But sometimes instincts are wrong. You have 9 top tricks now, and your hope for a tenth is some kind of spade-heart squeeze or pseudo-squeeze, barring a lucky heart position. East will certainly continue spades. Ideally you want to cash your good club and your diamonds ending in dummy with the ace of hearts entry to your hand. If you unblock the 10 of diamonds, you won't be able to get to your hand to cash the king of clubs without messing up your entries. But if you don't unblock, things will go smoothly. You will win the ace of spades, cross to the 10 of diamonds, cash the king of clubs, cross back to the king of hearts, and cash the last diamond, arriving at the desired end position.
You choose to unblock the ♦10. West discards the ♣7. East comes back the jack of spades. You win the ace, and cash your diamonds. East discards the ♠6 and the ♥2. West discards the ♠5 and the queen of clubs. Now what?
There isn't anything much you can do. If you cash the king of hearts and West drops an honor, you wouldn't finesse anyway as that would risk the contract. All you can do is lead a heart to your ace, cash the king of clubs, and hope something happens.
You lead a heart to your ace and cash the king of clubs. East guards the hearts, and you make 9 tricks. The full hand is:
How was the defense?
Holding only 2 clubs, East could see that a club continuation couldn't ever accomplish anything. He probably should have shifted to a spade at trick 2. This shift would give declarer some nervous moments. As the cards lie it wouldn't matter, since declarer could duck the second round of spades. But it is still East's best shot. If the spades had been 4-4 the spade shift would have defeated the contract unless declarer does better in the diamond suit.
After that, the defense was as good as possible. The discards were such that declarer couldn't read the black-suit distribution.
At the other table, North declared 3NT after a 1♦ opening and a 1♠ overcall. He won the first spade trick, went after diamonds, ducked the second round of spades, and had the same 9 tricks.
While transfers are more common than 2-way Stayman, the 2-way Stayman approach works pretty well particularly with weak notrumps. Having a game force established as low as the 2♦ level gives a partnership the opportunity for very accurate bidding. It is somewhat the same as 2-way checkback after a 1NT rebid. It is worth the effort for any partnership to have meaningful sequences after this low-level game force.
Plus... it's free!