In this deal from an online league match, how should you play four spades after a heart lead and diamond shift?
Since West is likely to have the club king, declarer should take steps to force the defenders to open clubs for him.
Declarer must finesse the diamond jack. He then leads a low spade to his five and ruffs a heart. A further low spade goes to East’s ace. Back comes a trump, and South wins in hand for a further heart ruff.
Now declarer cashes the diamond ace and king before tackling clubs, with West now marked with the king. Playing the club ace and another club only allows for K-x with West, who would probably have done more bidding with 6-5 shape. It is better for declarer to lead a low club from dummy instead. This still picks off king-doubleton while giving declarer the extra chance that East will not contribute the 10 or jack. If East fails to do so, declarer can insert the nine to endplay West, forcing a club return or a ruff-and-discard.
Say East finds the best defense of putting in the club jack or 10 — what now? It all depends on who has the other club honor. The odds are close between playing small, to freeze the suit, and covering, to endplay West if he has the king and 10.
Note that East could have broken up the endplay earlier on if he held one of the jack or 10 but not the other, by shifting to that suit when in on the spade ace. Declarer should therefore play small and then insert the club nine on East’s club continuation to score up his game.