A defence from the duplicate at Cheadle Hulme in January.
Love All matchpoints Dealer South (deal rotated)
(2) Transfer to spades
Partner leads the five of diamonds (second or fourth) and declarer plays the jack from dummy, how do you defend?
It looks as though partner has made a passive lead from three or four small. So declarer has three points in diamonds and 9-11 points in hearts and clubs.
Partner would have lead an honour from a combination such as KQ or AK, so it is possible, though tedious, to go through all the combinations of honours that declarer can have in the rounded suits. It turns out that when declarer has KQ or AQ of hearts and the ace or king of clubs it is vital to play a club through before the hearts are set up for a club discard from dummy. This has to be done immediately, so winning the first trick with the diamond ace and switching to a low club is the best defence.