🚀 go-pugleaf

This problem is based on the August 4, 1984 column by Alfred Sheinwold.

	North			SOUTH	WEST	NORTH	EAST

    S: KQ984			2 NT	Pass	3 S	Pass
    H: 42			3 NT	Pass	4 D	Pass
    D: AQ97			5 D	Pass	6 NT	All Pass
    C: T9

	South			As south starts berating his partner
				for not bidding 7 diamonds (even though
    S: A6			south is mostly at fault), he wins the
    H: AK53			J of hearts lead and plays A of spades
    D: KJT8			and a spade, winning the king.  East
    C: AK4			shows out.  Obviously, south erred by
				not finessing the 8, which would have
				guaranteed the contract.  Can you now
				help south make his contract?  (Not
				that he deserves it.)
########################################################################
	West		East

	S: JT752	S: 3
	H: JT9		H: Q876
	D: 4		D: 6532
	C: 6532		C: QJ87

South's best line is to immediately duck a HEART.  South wins the return,
cashes his red winners and the spade, ending in dummy.  West must keep a
spade, east a heart, so neither can guard clubs.  The club 4 is the twelfth
trick.  This line is guaranteed any time west has 3 or fewer hearts.
Cashing more than one diamond before the heart duck would be fatal on a
spade return, since entries would be messed up.

A spade duck rather than a heart will not work.  If a minor suit is returned,
the squeeze will work, regardless of who has the long hearts (a compound
squeeze, with both east and west giving up one of the suits they both guard),
but a heart return will destroy the entries.
(TYP J6a: try the play if a minor is returned after a spade duck.)

I received one correct answer from Rob Buchner.