Slams are based on controls (Aces and Kings) and tricks. Bidding no trump slams with balanced hands is simple arithmetic as noted in an earlier post. When you have a “Source of Tricks” Suit and your partner opens the bidding, your mind should go to slam!
You hold: ♠KQxx ♥A ♦x ♣AKQJ9xx. Your partner opens 1♦. You bid 2♣ (game forcing). Partner rebids 2♠. You bid 4NT (Roman Key Card for spades) and partner shows two without the Queen. At this point, my partner simply bid 7♠ which is wrong. The next bid should be 5NT, asking for King and guaranteeing possession all five Key Cards and the Queen. Partner will show you either one King or the specific diamond King, depending on your system. The correct bid at this point is 7NT. When you can count 13 tricks, NT is a safer contract—nothing could get ruffed on the opening lead which can occur in a suit contract—and it scores better. Plus, if partner does NOT have the ♠J, a 4-1 spade break could scuttle 7♠. If spades don't break, your fourth spade goes on partner's the ♦K. Partner is likely to have at least one club on the auction, and unless clubs are 5-0, you are making seven club tricks, three spades, two diamonds and one heart. That equals 7NT. Sad to say, in an 18-table field only four pairs bids 7NT. Three bid 7♠. 3 bid 7♣. One bid 6NT. Two bid 6♠. Three bid 6♣ and two bid 5♣.
TRUMP SUIT PREFERENCE REVISITED
You hold: ♠J94 ♥K1065 ♦J107 ♣Q83. Partner opens 1NT—weak, showing 11-14 HCP. RHO passes. You pass and LHO bids 2♠ [no alert] All pass. Partner leads the ♦A and you are looking at:
♠Q ♥J873 ♦Q8643 ♣J64
♠J94 ♥K1065 ♦J107 ♣Q83
Partner's opening lead is ruffed by Declarer. Declarer then plays the ♠3 and partner takes the ♠K. It may seem natural to play the ♠4, but you and your partner play trump suit preference and you should prefer a heart lead to a club lead. Keeping your ♠9 is false frugality. Declarer has a minimum of six spades on this auction. In that case, spades are 3-3 and you, personally, will only get your ♠J on the third round of the suit. The ♠9 will be immaterial. Partner needs to know which suit to play next, and if you play your lowest spade, she will (incorrectly) shift to a club and give Declarer an overtrick. A heart shift by partner will hold the contract to two.
You might think that partner could just continue diamonds, but she will not want to set up Dummy's ♦Q in case Declarer CAN reach Dummy later. Plus, if you imply possible club cards, partner has a doubleton and will be more eager to lead it, hoping for a ruff.