ORLANDO-FALL NABC 2016-NOV. 24-DIC. 4
November 26 
You open 1, partner bids 4, known as a «splinter» bid, showing a singleton heart, four or more spades, plus opening bid values. You have too good a hand to fool around. Partner must have minor-suit honor cards. You bid 4NT, RKCB with 1430 responses. Partner makes a second-step response of 5, showing 0 or 3 keycards. Given partner’s strong bid, partner must have three keycards: both missing aces plus the K. East doubles the 5 response. Undaunted, you continue with 5NT, asking for specific kings up the line. If partner has either minor-suit king, you can count 13 top tricks and will bid 7NT. Alas, partner denies a king by returning to the six level of the agreed suit, spades. I know you would bid 6NT after partner bids 6 with the South hand. It is clearly the right bid, but I want to see how you play 6 with the 5 lead.
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In a contract of 6NT, you would play low from dummy and claim after East took the king. It would also be quite reasonable to play low from dummy in a contract of 6 had there been no double. However, with the double and the K placed to your right, you have a safer play. After all, the lead could be a singleton! Go up with the A, draw trumps, strip hearts, discarding two diamonds from dummy, and exit with a diamond to East’s king, stripping both your hand and dummy of diamonds. East, in with the K, has no answer and you have made your slam the hard way.
The full deal:
As it happens, East tipped the duke by doubling 5. Had East not doubled, West would have led a diamond anyway and you might have gone down playing low from dummy. If the lead isn’t a singleton, playing low ensures 12 tricks.