This deal was misplayed at both tables of the 2018 Spingold semi-final. With no opposing bidding, South reached 3NT on this layout:

9  AK9764  73  A1052

KJ74  53  KQ104  KQ4

At both tables a 4th-best 5 was led to the ace and the 6 was returned. Both declarers covered with the 7, losing to opening-leader's 8.

At Table 1, West exited with the 2. Decide what you would do before reading on.

At Table 2, West exited with the 8 to the A and the 2 was played. Declarer had lost the first three tricks and hoping to set up hearts, he won his K. He played a heart towards dummy. All he had to do was duck a heart to East (spades looked to be 5-3) to make his contract.

LHO inserted a high heart so declarer won in dummy and came to the K to try another heart. Again West inserted a high one. Drat. Declarer won in dummy again, but East threw a club. This was the remaining position:

-- 976  A105

J --  KQ10 Q4

RHO had begun with 3 spades and 1 heart. Declarer now had a sure thing, but got it wrong. He can come to the Q (LHO showing out) and cash the top diamonds. If the jack falls, 9 tricks are his. If it doesn't fall, he cashes the Q and throws RHO in with the known J to lead into dummy's A10. Instead, declarer cashed the high clubs throwing East in with the J and then had to guess diamonds on East's diamond exit (he did--full deal below).

Back at Table 1, did you figure out the percentage play in hearts? If they are 3-2, nothing matters (the contract makes with 5 hearts, 3 clubs and the K). If they are 4-1 with East having all 4, the suit can't be picked up. But, if they are 4-1 the other way (they were), the only holding that can be picked up is specifically singleton 8 with East (it was).  No other 4-1 break can be picked up (if you don't see it, try laying out cards). Instead of correctly inserting dummy'2s 9, he instead went up with the A and eventually failed in his contract.

This was the Real Deal:

Vul:Both Dlr: West	9  AK9764  73  A1052
Q10853  QJ102  J98  8		A62  8  A652  J9763
	KJ74  53  KQ104  KQ4