and Dummy's, the defenders must strive to maintain communications between their hands. It is usually more difficult for the defenders to do so, because 1) the defenders cannot see each other's cards, and 2) the declaring side generally has the majority of high cards and/or trumps, cards which provide entries.  An alert Declarer will try to find ways to disrupt the defenders' communications.
2) North (Dummy): 
 ª 63   ©K52   ¨AT2   §KJ632
     
South (Declarer):   ªA52 ©A76   ¨K743   §QT5
Again the contract is 3NT. West leads the King of Spades. How should Declarer plan the play? We can count five top tricks (1 Spade, 2 Hearts and 2 Diamonds). We will need 4 more. We have several fast losers after the Spade Ace is gone. The only way to get the four additional tricks we need is the Club suit. We can take four tricks in the suit, and we have at least 2 entries to Dummy. But we will have to let the opponents in with the Ace of Clubs; we must hope that they cannot cash enough Spade tricks to set us. If Spades are 4-4 we will be safe, losing only three Spades and one Club. But what if Spades are 5-3 (or worse)? Is there anything we can do in that case? Yes, if the hand with the long Spades does not have the Ace of Clubs. All we need to do is play low from hand on the first Spade. If West continues Spades, we play low on the second Spade as well. We must "hold up" or Ace until the third round. Now we knock out the Ace of Clubs. If the opponent with the Ace has three or fewer Spades, he will not have any more Spades to lead to partner. Similar to the "duck", which is used to preserve our own communications, the "hold-up" play is used to disrupt the opponents' communications. It is vital to win a trick at precisely the right time. Of course, tactics like the "duck" and "hold-up" are available to the defenders as well:

3) North (Dummy): ªK4   ©9   ¨8742      §KQJT76
    South (Declarer):
ª AQ6   ©A7653   ¨AK3   §92
The contract is 3NT. West leads the ª2.  How should Declarer plan the play? 
We can count three Spades, one Heart and two Diamonds for a total of six tricks. We will need three more. These will have to come from the Club suit. We should be able to take five Club tricks, more than enough for our contract. Are there any potential problems? While in most cases it is best to honors in the short suit first, in order to avoid blocking the suit, there are more important considerations here. The King of Spades is the only side entry to dummy. Of course, the defenders are allowed to use the hold-up play as well. They will probably hold up their Ace of Clubs until the second round. We will need that Spade King to get back to Dummy. So we must win the first Spade in our hand, temporarily blocking the suit, and lead Clubs. The opponents will win their Ace, and we will return to Dummy with the Spade King to run the rest of the Clubs.  A careful Declarer makes use of every possible entry:

4) North (Dummy): ªJ3   ©Q863   ¨742   §KQ43
    South (Declarer):
ªK6   ©J52   ¨AQJT   §AJ92

The contract is 3NT. West leads the ª7 to East's Ace. East returns the ª2. How should declarer plan the play?
We can count six tricks (1 Spade, 1 Diamond, and 4 Clubs). We need three more.  We
have six or more losers (2 Hearts and at least 3 more Spades, in addition to the Spade we have already lost). We will have to win those three tricks without letting the opponents in. Those tricks can only come from the Diamond suit. We will need to find the Diamond King with East. We will need to take the diamond finesse, and will probably need to repeat the finesse sev

eral times. We have only 2 apparent entries to Dummy - the §K and §Q. This will be enough if East has no more than three Diamonds, but what if East has four or more? Perhaps the Club suit will give us that third entry. We can cash the §A and lead the Nine of Clubs to Dummy's King. If both opponents follow, we can get a third entry in the club suit. When in Dummy, we take the Diamond finesse. Assuming it wins, we lead the Jack of Clubs to Dummy's Queen and repeat the Diamond finesse. Now we can get back to Dummy by leading the two of  Clubs to Dummy's three, and take one more Diamond finesse. If an opponents shows out on the second round of Clubs, we will only have two entries to dummy, and will have to hope for East to have no more than three Diamonds. But careful planning gives us an extra chance. About 15% of the time East will have four or more Diamonds to the King and two or three Clubs. If Dummy's Spades were Qx, we could assure ourselves of an extra entry by playing the King under East's Ace at trick one - although East might counter this by not playing his Ace at trick one.

5) North (Dummy): ªK4   ©92   ¨AJT983   §52
     South (Declarer): ªA62   ©A7653  ¨K   §A943

The contract is 3NT. West leads a Spade. How should declarer plan the play?
We have four tricks outside the Diamond suit. We will need five diamond tricks for the contract. We have only one side entry to Dummy. If we unblock the
¨K, go to Dummy with the ªK and lead Diamonds, we will need to find the ¨Q singleton or doubleton - less than a 20% chance. Is there anything better?  We actually have two entries to Dummy - the ªK and the Diamond Ace. We must win the ªA and lead the ¨K, overtaking with the Ace in Dummy. Now we can lead Diamonds until the defenders win their Queen, and return to Dummy with the ªK to cash the rest of the Diamonds.

6) North (Dummy): ª74   ©9652   ¨AK   §J8532
      South (Declarer): ªAKQJ6   ©¨QJT985   §4

The contract is five Spades. (Not every hand is played in 3NT). West leads the Ace of Hearts and continues with the King of Hearts. How should Declarer plan the play?
We have eleven winners and two losers. The problem is, the Diamond suit is blocked. If Spades are 3-3, there will be no problem - we can draw trumps and take the A-K of Diamonds. Now we can return to our hand with a Heart ruff and cash the rest of the Diamonds, making our contract. But what if Spades are 4-2? We have to trump the second Heart, leaving us with only four trumps. Now we must use up all our trumps to draw the Opponents' trumps. After cashing the A-K of diamonds, we will have no way to get back to our hand to cash the rest of the Diamonds. If we cash the A-K of Diamonds first, we will be set if Diamonds break 4-1 or 5-0. Is there any way to handle a bad break in both suits? We don't need the ¨AK. The Diamonds in our hand are good enough. All we need to do is discard Dummy's A-K of Diamonds on the third and fourth round of trumps. Now we are in our hand to cash all the Diamonds.  We have not actually created an extra entry; we have avoided a "blocked" position, which saves the need for an extra entry - an entry we do not have on this hand. (If our Diamonds were slightly weaker, QJT432, we would have to cash one of Dummy's honors first, draw trumps, discarding the other honor.)