The aim of the hold up is lead or tempo value reduction: The object is to reduce the value of possible entry-tempi in one opponent’s hand. Put into simple words, the aim of the hold up is to exhaust the led suit in the hand of one opponent in order that, should he later gain entry, he is unable to lead it.
After the hold up it is assumed his leads cannot be put to such good purpose. If, therefore, an opponent’s leads could be put t a better use than leading his partner`s suit, the hold up should not be made, fot the value of his leads are not thereby reduced.
Whether or not it is expedient to hold up is, of course, often a matter for conjeture.
Here is a hand wich shows how effective the hold up can be:
 K J 4 A J 3 6 3 A J 10 8 2 |
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| 6 5 9 8 2 A 10 8 5 4 2 9 7 |
Q 10 9 3 7 6 5 4 Q 9 K 6 4 |
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| A 8 7 2 K Q 10 K J 7 Q 5 3 |
The contract is 3NT by South. West leads the 5. East plays the Q and declarer decides to hold up. allowing East’s queen to win. He does this because he is obliged to finesse the clubs towards East’s hand.
Had be been able to finesse to duck in the club suit towards West’s hand, be would have taken the first trick with the King, since he could again stop the diamonds should West lead them.
As it is, after having taken the first trick with the Queen, continues the diamond suit. It cannot now, however, be broght in, for the when East obtains the lead through his K he will ot have destroyed the value of East’s lead.