The expert declarer runs into just as many difficult guessing situations as anyone else, but usually manages either to guess right or to somehow avoid the guess altogether.

For example, take this deal where West leads the four of diamonds against three notrump. Declarer wins East’s jack with the queen, bringing his total to eight sure tricks. The question remaining is how he can give himself the best chance to develop a ninth.

One possibility is to lead a club to the king at some point in the play, hoping that East has the ace. Another possibility is to rely on a spade finesse against the queen. The trouble with this is that South has to guess which way to take the two-way finesse.

But declarer’s best approach by far is to make no effort whatsoever to guess where any of the missing key cards are located. Instead he enlists West’s aid by forcing him to break one of the two critical suits.

After winning the diamond lead, South cashes the K-Q-J of hearts and then plays the ace and another diamond. This allows West to cash his three diamond tricks as South discards two clubs from dummy and a heart and a club from his hand. Whatever West plays next, however, whether a spade or a club, presents South with his ninth trick.

Note that in setting the stage for the endplay, South must be careful to cash only three heart tricks, not four. If he cashes all four hearts before putting West on lead with a diamond, he may have trouble discarding on West’s last diamond and might go down one against best defense.

Tomorrow: Bidding quiz.