Regular partnerships have firm agreements about leading honors against no-trump. One of the more sensible agreements is that from ace-king combinations, you lead the king if you want your partner to unblock the queen or jack, while the ace asks for attitude. Under the king, third hand drops an honor if he has one, or signals count.

Today, against three no-trump West leads the heart king and East follows with the 10, suggesting a four-card suit. Now West knows a heart continuation would set up South’s queen, so he shifts to a club. Declarer wins the king and has to find a way to a ninth trick.

While declarer could hope to develop a trick from the spades, diamonds offer far more hope. At trick three, declarer must lead the diamond eight from the board, as a sort of avoidance play. He is trying to set up a diamond trick while keeping East off lead. This approach will produce two tricks when East has only one of the diamond 10, queen or king.

Here West wins the diamond and plays a spade. South wins in hand, leads a club to the board, then plays the diamond jack, intending to let that card run if East plays low. When East covers, declarer wins the ace and plays a third diamond, thus setting up the long diamond for his ninth winner.

It happens more often than it should that declarer falls at the first hurdle – by miscalculating whether to duck or win the trick. Today, when West leads the spade six against three no-trump, East covers the 10 with the jack. How do you plan to make nine tricks?

If you let the spade jack hold, East will shift to the heart queen very smartly and, as he has two entries to his heart suit, you will lose a spade, three hearts, a diamond and a club for down two.

So you must win the first trick and then decide which minor suit to play next. I hope you will see that you should play on diamonds next, because tackling clubs first would see you lose the contract whenever West began with five spades, as well as the diamond ace, and East started with the club king.

So you should lead the diamond king next. East wins his diamond ace and exits with a spade. Only now do you duck the spade, severing the link in spades between the defenders’ hands.

You will win the next trick in hand and take the club finesse by running the club nine. East will win the king and will have no spade to play. So you will make two tricks in each of spades, hearts and diamonds, plus three in clubs.

Note that even if East did have a spade to play, you would still take nine tricks as long as spades were originally 4-4.

In today's deal South might have looked for a slam after the two-no-trump rebid. Over the forcing rebid of three spades, North can cooperate with slam interest or sign off in no-trump or spades with a minimum in context.

As it was, though, it was just as well that South restrained himself, because even 10 tricks proved quite difficult to accumulate. West led the heart queen and declarer rightly refused to play dummy’s king on the first two rounds. (If West held Q-J-10-x-x, East’s ace would appear on the second round and dummy’s king would be worth a trick.)

But how would you continue the play when the defenders take three heart tricks and East then switches to a club? You win in dummy and run the trump nine successfully. When you lead dummy’s last trump and finesse the queen, West shows out. What now? You must aim for a trump-coup end-position where you hold A-J of trumps in your hand and the lead is in dummy. Because of the shortage of entries to dummy, you must cross your fingers and lead a diamond to the 10, ruff a club, re-enter dummy with the diamond queen, and ruff another club. When you cross to dummy’s diamond ace East follows suit, and you have reached the required two-card end position. Your A-J of trumps sit over East’s K-8 and the lead is in dummy. You can play a club and take the rest whatever East does.

In today's deal West knew that his opponents were in a thin three-no-trump contract (East had to have a few points for his voluntary heart bid) and so was reluctant to lead a heart, which could easily have given declarer a trick. Instead, he chose what he hoped was a passive diamond, and in a way he was right because the diamond did not give anything away.

Declarer won in hand with the queen, played a club to dummy’s jack and East’s 10, then led a club back to his queen, East following with the 10 and the nine, West winning his king.

West now switched to the heart queen, which held the trick. What now? West continued with another heart, won by declarer’s ace, and declarer rattled off four more club tricks. At this stage declarer had seven tricks and needed two more. Everyone was reduced to four cards, and as dummy was discarding after West, there was an answer to anything the defense did. West’s best shot was to come down to three spades and a singleton diamond ace. But declarer simply kept two diamonds and two spades in dummy and led a diamond up.

When the heart queen held, what West needed to do was cash both his aces before he played another heart. Since East had given count in clubs and hearts, West might have been able to work out declarer’s shape. This defense forces declarer to give East a heart trick after he has cashed his clubs.

Today's problem comes in two parts. Let's look at the opening lead first: What would be your choice as West here? You shouldn't seriously consider leading partner's suit. He hasn't bid it voluntarily — you dragged the bid out of him, and when he had the chance to double a club cuebid, he did not do so. Declarer rates to have six spades and four diamonds, so a club lead could be straight into a tenace. A top heart looks safe, but a trump is best, hoping to protect your holdings in all the outside suits. A trump will not always be safe, but the odds favor it not doing anything for declarer that he might not be able to do for himself. And you might kill a diamond ruff in dummy. And today it would defeat four spades.

But let’s see what the expert declarer did in four spades on the lead of the heart king. He won, cashed the spade ace and king, then led a diamond from dummy to his queen and ace. West was forced to return a diamond, and declarer won in dummy, unblocking his diamond eight, and played a third diamond to his nine and West’s 10, East pitching a discouraging club. What could West do now? Hoping that the diamond six would not prove an entry, he played the heart queen. Declarer ruffed, played the spade queen and another spade, and could win the club return with the ace, then cross to the diamond six to discard the club queen. Contract made!

One of the most difficult decisions as a defender is to know when to switch the point of attack when your opening lead appears to have been successful. Take this hand, from the 2008 European Championships match between Iceland and Norway.

In response to his partner’s overcall, West, Norway’s Terje Aa, led a heart and declarer, Sverrir Armansson, correctly allowed Jorgen Molberg’s nine to hold, expecting the suit to be divided 5-2 or 6-1. Had East continued hearts, declarer would have prevailed. So long as East held no more than one club honor, Armannsson would have had time to set up two club tricks. Although East could establish his hearts, he wouldn’t have the entry to enjoy them.

But Molberg found the killing switch to a spade. With a heart trick in the bag, the defenders were able to establish two spade tricks before declarer could set up his clubs.

In the other room Norway’s Geir Helgemo, North, opened one no-trump and East did not overcall. After a Stayman sequence, North ended in three no-trump and East led the heart queen. Without an overcall to warn him, declarer had no indication that hearts divided 5-2. The most likely heart division was 4-3, so the odds favored winning the first trick rather than ducking and risking a spade switch. But luck was with Helgemo. When declarer led a low club from dummy, West did not work out to fly with his king, and East won the trick (yes, ducking would have been better), allowing declarer to prevail.

To be third in hand at favorable vulnerability after two passes is a delightful position. You know that your left-hand opponent has a good hand so you can make life as difficult for him as you dare.

Here West had a good club suit and virtually no defense, so he opted for the three-level pre-empt, which worked very well. North’s takeout double was clear and South was happy enough to bid his reasonable five-card diamond suit. That ended the auction.

After cashing two rounds of clubs, West had to decide what to do next and he found a good play, the opportunity for which crops up quite frequently if you are on the lookout for it. He switched to the spade THREE.

Declarer won with the ace and no longer had a winning line. As soon as East got in with a red-suit trick, he could play another spade, establishing his own queen, which he could cash when he was next on lead.

Declarer now cashed the diamond ace and played hearts. East took his ace and led a second spade. Declarer won and continued with hearts, hoping that East had four hearts and three diamonds, but West ruffed with his diamond seven, and three diamonds went down a trick.

Note that if West had switched to the spade jack, that would have sunk the defense, for East would not have been able to continue the suit when he got in.

When the opponents pre-empt, you are often forced to guess, as in today’s deal. But how unreasonable is it to bid slam here, hoping for the spade queen or spade length in dummy?

The defenders lead the heart queen to your ace. You cash the spade ace and your worst fears are realized when West discards on this trick. What should be your plan next?

You must now strip all the clubs from the hand that has the diamond ace. If East has only two clubs, you need to decide which defender has the diamond ace, but why not cash two clubs to see if you can find out more? Best is to lead the club queen first. After all, West may give you honest count if he thinks his partner needs to know when to take his club winner.

When you cash a second top club, you discover the club break, so it is quite safe to take just one of your remaining club winners (not both!), then lead a diamond. You need West to have the diamond ace — if East had it, he could exit with his last club. When West wins and plays a red suit, you win in dummy, pitching your club from hand and take the spade finesse.

Note that had you cashed your last club before leading your diamond, whoever wins the diamond ace can play a second diamond and force you to ruff in hand, preventing you from taking the spade finesse.