South to make 6♠ on a spade lead.

Declarer cannot proceed without drawing trumps lest the defence cross-ruff. So he overtakes the spade queen to draw all four rounds but what does he throw from dummy? Unable to take a finesse in hearts himself, he recruits East for the task. On the spades he discards three top diamonds (or at least two of them).

South then wins three diamonds ending in hand retaining the deuce; this he now plays to east who, after eight tricks, only has hearts left. His forced lead scoops West's heart king and dummy, now comprising ♥ AQJ109, is high.

South to make 6♠ on a spade lead.

Again South must draw trumps but this time after they are all gone, he can enjoy the diamond suit in the usual manner, scoring five tricks.

Down to just four cards, what can East keep? If he retains two hearts and two clubs then a club is played; if East does not win the ace he is end-played with it next trick and if he does, he has the unattractive choice of leading a heart or conceding the rest to South's king and the remaining small clubs.