As I have often remarked, one cannot persuade one's opponents not to do something just because one earnestly wants them not to do it. If you want to prevent them from making a play, you have to work a little harder at it than that.

Take today’s deal, where South reaches four spades on an unopposed auction, after North’s slightly pushy raise to game. Your partner leads the diamond 10. Declarer plays low from dummy at trick one, you encourage, and declarer takes the diamond ace and advances a low heart, to the heart eight from your partner, and dummy’s 10. Plan the defense.

When declarer leads a heart, partner’s heart eight shows an even number, almost certainly in this case a four-card suit. You must duck this trick, to prevent declarer getting two heart tricks later on.

Of course you don’t want to let declarer get to dummy to lead out the spade queen and capture your king. But since you cannot prevent South from taking the spade finesse sooner or later, you might as well not give him anything in hearts to which he is not entitled.

If you duck trick two, declarer will now take the spade finesse and run his trumps, then exit with the heart queen. However so long as the defense retain their club guard, they can take the heart queen and lead out winning diamonds at every turn. Declarer will eventually have to concede three minor-suit losers to go with the heart ace, for one down.

In today's deal from a team game, both North-South pairs stretched to a very poor game, when North hoped that their spade suit would provide significantly more tricks than it actually did. Plan the play on a low diamond lead.

Things look pretty hopeless, don’t they? Playing for hearts to be 3-3 needs a lot more to work than just that. For example, if diamonds are 5-2 and West can get the lead with the second round of hearts, you will go down. Even if diamonds don’t defeat you, you still need the club queen to drop before you have nine tricks.

In one room declarer followed a line that relied on a misdefense, which didn’t happen. However, in the other room, South played for the layout that actually occurred and found his way home.

At trick two he crossed to dummy with the spade ace and played a heart toward his hand, realizing when East followed low that it would not help him to find the heart 10 right; only the king-queen onside would do. When his heart jack held, he continued with the heart ace and another heart. When West showed out, declarer’s main chance in hearts had gone. But the 5-1 spade break was a curiously favorable outcome. With the club queen dropping in two rounds, it meant that the defenders could take no more than two hearts, one diamond and one spade. If the defenders had set up dummy’s spade winner, declarer would have come to a different nine tricks.

It was a sad loss to the world of bridge when Giorgio Belladonna died nearly 20 years ago. As a part of the legendary Italian Blue Team, he had 13 World Teams wins and three Olympiad victories to his credit. Belladonna is best remembered for deals like today’s – which has been referred to as the “Striptease Coup”.

Playing South, Belladonna ended in five clubs, against which West led the spade king. Now it looks as though declarer was facing three losers. South won in hand, cashed the diamond queen, and crossed to the heart 10 with the intention of discarding his losing spade on a top diamond. East ruffed with his club two, and South overruffed. Next he tried the hearts, again hoping to discard dummy’s losing spade. No joy, as the third round of hearts was ruffed by West with the club eight and overruffed on the table.

So far so bad; and when dummy’s last top diamond, the king, was led, ruffed low and overruffed, declarer still had a losing spade in each hand. But the good news was that the defenders had now used up all of their small trumps. The consequence was that one of declarer’s trump losers had evaporated, and now the diamond ace and king fell on the same trick — contract made. At the other table the contract was four hearts. This failed after a spade lead, when declarer tried to establish his clubs and lost trump control.

Against South's four spades, reached after North had shown a good hand with four trumps while South had temporized with a three-heart call, which simply marked time rather than guaranteeing four hearts, West led his singleton diamond. East, who had shown his diamonds in the auction, played the king, ace, then six of diamonds, declarer contributing the four and jack, then pitching the club nine. What do you plan to lead to trick four?

This is a trick question, of course. You do not plan to be on lead to trick four, since there is nothing to be gained and everything to be lost by ruffing in on this trick. You would be ruffing with your trump trick, and declarer would later be able to discard a second club loser on dummy’s diamond queen. Effectively, you are ruffing in on air with your trump trick and letting declarer use his winner later on. By discarding a club on this trick, you allow declarer to take a discard — but you could never have stopped him from doing that whatever you did.

The point is that if you save your trump trick for when it matters, your side will later come to both a club and a trump trick. And note that if declarer does have four hearts and two clubs, nothing you do matters.

Incidentally, East might well have guessed to shift to a club at trick two to protect against just this eventuality; but that is no reason for you to misdefend.

When West leads a low trump against six spades what should your plan be, as East follows to the first round of trump?

Rather than focusing on the deficiencies of dummy when it comes to high cards, you should concentrate on the deal, and realize that you have an inevitable diamond loser but can ruff two of your diamonds in dummy. You can make your slam by relying on either one of the club or heart finesses (each one in principle being a 50% chance).

However if you can, you should seek to find a way to combine those two chances. Your secondary chance here is to ruff out the heart king in three rounds; you will combine this with the club finesse.

So you win the trump lead, cash the heart ace and ruff a heart high. You then cross to the spade jack (drawing the last trump) and ruff another heart. Next you give up a diamond, preparing for two diamond ruffs in the dummy. If the heart king fell from either defender, you will discard the club queen on the established heart winner after taking a diamond ruff. Otherwise you will finesse the club queen, taking your second chance. Just for the record, your additional chance improves your original 50 percent odds to 60 percent — not to be sneezed at.

This problem comes from a bridge book for beginners (this being one of the tougher hands), Planning the Play of a Bridge Hand, by Barbara Seagram & David Bird.

In his contract of three no-trump, declarer formed a master plan, with a fallback plan ready to go. Unfortunately he missed one small detail, and his house of cards collapsed.

Against the no-trump game West led the spade queen. Declarer won in hand and saw that the quickest way to his contract was to take four club tricks. This was Plan A, so at trick two he led a low club to the king. If the king held, his intention was to return to hand in diamonds in order to lead a second club up. Should the ace still not have appeared, he was ready to resort to Plan B – the heart suit. Even with the heart king offside, three heart tricks plus two in each of the other suits would add up to nine tricks.

But South’s plan had overlooked one minuscule detail. The club he initially chose to lead toward dummy was the three. East won with the ace and returned a spade. Declarer won and played a second club to the queen, and when East showed out the suit was irretrievably blocked. So Plan B had to be put into action. When the heart king was offside the game was sunk.

Declarer could have allowed for this distribution of the club suit by leading the nine at the first opportunity, and later unblocking the eight as well. The three could then have been utilized for a finesse of the seven.

Here is a defensive problem for you this week, so you may choose to cover up the East and South hands before you read on, putting yourself fully in West's shoes.

In my view the opening lead against three no-trump is far from clear-cut. It is nearly certain that South holds the guarded spade queen, so leading a low spade may well give the ninth trick, while leading a top spade also risks severing communications between the two defensive hands. However, at most tables West did lead a top spade, and continued with a second top spade at trick two, East discarding a discouraging club. What now?

This deal occurred in the round-robin match from the 2008 Olympiad between the German and Dutch women’s teams. The play had started identically, but now the paths diverged. The Dutch West continued with a third spade. Declarer won, conceded a club, and was soon able to claim the remainder of the tricks.

This line of defense was surely an error by West, as there is no room for East to hold a club honor and the diamond ace, so you have no realistic chance both to set up spades and cash them.

At the other table, the German West (Daniela von Arnim) found the better defense of switching to a low diamond. Dummy’s 10 was covered by the queen and ace. Declarer played ace and another club, and when East won and continued diamonds, this set up enough diamond tricks to defeat the hand.

One of the most interesting play or defend problems from the summer nationals last July in Atlanta confronted Glenn Milgrim, who declared three spades doubled, after some optimistic bidding from both members of his partnership.

Milgrim won the club lead and ducked a diamond to East, Richard Oshlag, who resisted the temptation to play trumps when declarer would have set up the diamonds. Instead, he carefully reverted to clubs to kill the dummy entry.

Oshlag won the heart exit from dummy to play a trump, and declarer could take only two aces and six trump tricks when West, Paul Munafo, ducked his trump king.

Afterwards, Milgrim was kicking himself for missing a beautiful play. The way home at trick four is to play the diamond ace and ruff a diamond, after which you must ruff a club — but take care to ruff with the spade ace.

When dummy next leads a winning diamond, East must ruff in and declarer overruffs. If West discards, declarer will ruff a club in dummy for his ninth trick, so West must overruff and cash a heart. He must then exit with a trump to stop the crossruff, but thanks to that earlier high ruff, declarer can overtake dummy’s spade jack with his queen, draw trumps, and give up a club. He still has a trump to go with his fifth and master club. His nine tricks are four trumps in hand, the diamond ace, two clubs and two ruffs.