5. It appears that nothing can defeat the slam, so the first impulse is to draw trumps. But a lot of points are at stake, and every extra precaution is worthwhile. The distribution that can wreck the slam is a singleton heart in one hand and the singleton ace of spades in the other, allowing one defender to win the ace of trumps and give his partner a heart ruff. Stop all chance of such shenanigans by overtaking your king of clubs with the ace and discarding your ace of hearts on the queen of clubs before touching trumps. This hand and the next one are favorites of the noted British author, Victor Mollo (SI, Jan. 6), who has produced a bookful of them (How Good Is Your Bridge? Hart $4.95).
6. Trumps must divide if the slam is to be made. You might plan to ruff all three spades in dummy, but this exposes you to a diamond ruff when you try to get back to your hand later to draw trumps. Nor can you draw two rounds of trumps after ruffing the first trick in dummy, for the defenders will surely gain the lead with the high trump to cash the spade ace before you can discard both your remaining spades. The most effective plan is to ruff the opening lead, then play a heart from dummy and a low one from your own hand. Dummy still has a trump to handle a spade return, and you can easily get back to your hand to draw the rest of the trumps, later discarding your spades on dummy's clubs.
7. At first glance it seems that you can afford to ruff, draw trumps and claim. But if trumps divide 3-0 and clubs 5-2 you will be left with two losing cards (a club and a diamond) and only one trump in dummy with which to ruff. However, the opening lead allows you to plan a dummy reversal—to make the dummy the master hand by ruffing four spades with trumps in the closed hand. You should ruff the opening lead and enter dummy with the 8 of trumps. If either defender fails to follow, you should ruff a second spade in your hand. Lead another trump to dummy and ruff a third spade. Now dummy's jack of clubs allows you to ruff a spade with your last trump. Your remaining low club is ruffed, and when the last trump is drawn by dummy's king you discard your low diamond. The diamond ace is the entry to the good clubs in your hand.
8. Where's the puzzle? You can make seven spades by ruffing a couple of clubs in dummy. But that is exactly the source of the problem. You need only assure 12 tricks, if you can, against nearly any distribution. The possible fly in the ointment is finding either player with a singleton club, having the king of clubs ruffed and another trump returned. Now you have three club losers and only two trumps in dummy. To guard against even this slim possibility, you should forget about setting up your club suit and instead play to ruff dummy's losers, as in the previous hand. The king and ace of diamonds are followed by a diamond ruff, and dummy is reentered with a heart. The fourth diamond is ruffed with the queen of trumps, and the high heart followed by a heart ruff with the ace leaves dummy with three high trumps and two clubs. If all goes well, you will make 13 tricks, but even if someone ruffs a high club, 12 tricks are assured.
9. Either a successful spade finesse or finding the ace of hearts with East gives you your contract. But you can increase your chances by combining two lines of play. After winning the club opening in dummy, cash the ace of spades and ruff a spade. Enter dummy with a trump and ruff another spade. If both defenders follow suit, the fifth spade can surely be established. You draw the remaining trumps ending in dummy, ruff out the last spade and discard two hearts on the black-suit winners. If West shows out on the third spade, a spade trick can be set up by means of the marked ruffing finesse against East. Finally, if East shows out on the third spade, abandon the suit. Now try for your 12th trick by leading a heart up to the king.
10. Although it may go against the grain to ruff high on this deal, ruffing low could prove a costly economy. You should win the first trick, cash the king of spades and the ace-king of clubs, then ruff a club in dummy with the king. If you make the mistake of ruffing with one of dummy's lower trumps and East overruffs, the defenders can cash a heart to defeat the slam. You next discard your heart on the ace of spades, ruff a heart and ruff your last club with the 9. Either defender might score the jack of trumps, but that's all.
11. You have a certain club loser, so your efforts should be directed at avoiding the heart finesse, if that is possible. Accordingly, you should put up dummy's king of clubs, cash the queen and ace of diamonds and ruff a diamond with dummy's 10. If East overruffs you will have to fall back on the heart finesse, but if he follows to the diamond you are home. You return to your hand with the ace of spades, cash the ace of clubs and play your high diamond. If East follows suit or discards he is next thrown in with his high club, forcing him to lead into one of dummy's major-suit ten-aces. And if he ruffs the high diamond the outcome is the same. Either way you wind up with 12 tricks.
12. This puzzler is by my friend Paul Lukacs, perhaps the greatest living composer of single-dummy problems. At first glance it seems the contract depends solely on the club finesse, and if it wins you will make your contract with an over-trick, discarding both spades on the long clubs. But it is wrong to put all of your eggs in one basket, for if West has the ace of spades you have an additional chance to land your slam. You should win with the ace of hearts, draw trumps and then lead the 9 of spades. If the queen loses to East's ace, you can still fall back on the club finesse. However, the slam is ironclad if West has the ace of spades. If he plays low, dummy's queen will win. You then discard the king of spades on the high heart, ruff a spade and take the club finesse for a possible overtrick. If West instead hops up with the ace of spades and returns a club (his best play) you put up dummy's ace, return to your hand with the king of spades, overtake the queen of hearts with dummy's king and discard clubs on the queen of spades and jack of hearts. Note that if for some reason you feel that East has the ace of spades, you can reverse the procedure by leading a spade from dummy toward your king early in the play.