Opening lead — jack of clubs.
It is not uncommon for declarer to be in a situation where he can assure a contract by playing correctly, but can jeopardise the contract by playing incorrectly.
Take this deal where South wins the opening club lead with the king and, after digesting the 5-0 split in the suit, returns the queen of diamonds. If West knows his way around a bridge table, he ducks and allows declarer to win the trick. (If West takes the queen with the ace, South cannot be stopped from eventually scoring two diamond tricks and the contract.)
When the queen holds, South plays another diamond, and West ducks again. Declarer now has a tough decision to make because he does not know where the ace and jack are located. If he guesses wrong, he goes down.
Presenting declarer with such guesses is part of the strategy of defence, and any defender who misses such opportunities is selling himself short.
This having been said, however, the fact is that if declarer plays correctly, he makes the contract regardless of where the ace and jack of diamonds are situated. All he has to do is to lead the four of diamonds to dummy’s eight at trick two. This guarantees at least two diamond tricks against any lie of the cards.
If the eight wins, a low diamond to the queen produces a second diamond trick. If the eight loses to the jack, South later overtakes his queen with the king to assure two diamond tricks.
All roads lead to Rome — provided South has the presence of mind to play the diamond four to the eight at trick two. This eliminates any chance of going wrong later in the play.