Hands are from San Diego Bridge Club, October 16, 2018.
East: ♠10943 ♥KQ83 ♦Q10742 ♣—
West: ♠AKQ5 ♥A76 ♦A863 ♣J2
Partner begins an uncontested sequence with 1♦ in second seat. You respond 1♥ and partner rebids 1♠. With the double-fit—partner is at least 4-4 in the pointed suits at this point—the East hand is looking very good, so you jump to 3♠. Partner bids 4♦—showing a diamond control (could be ♦A or ♦K since we are below 4NT) and denying a club control—actually good news that partner does not have much, if anything, wasted in clubs. You duly bid 4♥ (still can be ♥A or ♥K below 4NT). Partner signs off at 4♠. Clearly partner has at least two quick club losers because she made a slam try, but did not use Blackwood. So you bid 5♣ (first round control since you are past 4NT). Partner duly bids 6♠.
The lead is a club. Partner ruffs in Dummy, plays a high spade to the her hand and ruffs another club in Dummy. Then pull the remaining trumps. The proper way to play the diamonds (missing the King and the Jack and the Nine) is low to the Ace and then low toward the ♦Q10xx. As long as diamonds are NOT ♦KJx behind Dummy, you are safe. (If opening leader had held a singleton diamond, he MIGHT have led it.) Diamonds cooperate and you make six.
East: ♠A2 ♥J83 ♦8732 ♣8763
West: ♠K75 ♥9542 ♦A5 ♣AK52
This hand was an exercise in bidding discipline and proper timing as far as Declarer play. West opened 1♣. North passed. East passed. South had a clear cut double with 4=4=3=2 shape and 12 HCP but choose to balance with 1♥ (don't ask me why). West passed and North bid 1NT. Now East bid 2♣ and all passed.
The lead was the ♥K, then a heart to the ♥A. Then RHO shifted to the ♦Q. You have two top spade tricks, two top club tricks, one top diamond trick, and can count on one spade ruff in Dummy. Since you know the hearts are 4-2, you would like to ruff your fourth heart in Dummy as well. You must hope that clubs are 3-2, or you cannot make the hand. LHO must have ♣Qxx or ♣QJx in clubs for the NT bid. You must DUCK the diamond. If South continues with the ♦J, takes the ♦A. Then cash two top clubs and play another heart. RHO can take the ♥Q, but doesn’t have the last trump. You can ruff two diamonds in your hand and one spade and another heart in Dummy. North can overruff at her leisure, but you take eight tricks.
If you do NOT duck the diamond, and pull two rounds of trump first, North can pull a third round of clubs when she is in with the ♦K, and you will not make the hand.
West: ♠AK105 ♥654 ♦8 ♣A9532
East: ♠J9743 ♥J982 ♦A109 ♣J
West opened 1♣. North passed. East responded 1♠, and West raised to 2♠, the opponents silent throughout.
The lead was the ♥K, then the ♥A, promising a doubleton (because the defensive agreement was to normally lead the ace from ace-king). Then LHO shifted to a diamond. You take your ♦A and must think about timing once more. You need to ruff two diamonds in Dummy which will be fine if trumps are 2-2. (If spades are not 2-2, you are probably losing the ♠Q anyway.) However, Dummy has a lovely, long suit which is worth trying to develop. So, you play your ♣J to the ♣A, and the ♣10 appears on your right. You ruff the second round of clubs as the ♣Q falls on your right. Now you cash top two spades and both opponents conveniently follow. You ruff a third round of clubs and the ♣K falls on your right. If you notice all the spots, the ♣9 in Dummy is now good (and will draw the ♣8 from LHO so the ♣5 will also score a trick).
You ruff your last diamond on dummy and discard two losing hearts on the good clubs.
Long suits are powerful resources—do not neglect them!