These hands are from Adventures in Bridge, September 25, 2018.
East (Dummy): ♠54 ♥K ♦K10943 ♣J7432
North: ♠Q9762 ♥864 ♦8 ♣AQ108
West opens 1♠. You (North) pass. East bids a Forcing NT, and partner chirps in with 2♥. This should show a GOOD hand because partner is entering a live auction. West bids 2♠. Your call?
Please bring out the red card! You have clubs. Partner has hearts, and perhaps something in diamonds as well. With your spade spots, you expect to take two spade tricks. Declarer is not going to make this. Yes, you have 3 puny hearts, but your 8 HCP opposite partner's expected 13-16 is unlikely to make game on this hand. Prefer to defend (not declare) when you have length in an opponent's suit and game is unlikely. You meet the “Rule of 2 and 4” for 2-level penalty doubles: at least 4 trumps and at least 2 trump tricks.
You lead the ♥8 (top of nothing), and partner grabs the ♥A. Then she cashes the ♠A and returns a fourth best heart which Declarer takes with the ♥Q. Declarer then plays a diamond to Dummy's ♦K which wins. The second round of diamonds goes to Declarer's ♦J as you ruff. When you return another heart, Declarer takes that with the ♥J.
Declarer cashes the ♠K and leads the ♠J to your ♠Q. Now what?
Count partner's high card points. She has shown up with the ♠A, the ♥A, and the ♦Q. She MUST have the ♣K. Take your ♣A (to protect your partner from making a mistake if you play a low club), and then play a low club to partner's ♣K. She will return another diamond, allowing you to score your ♠9. Declarer will be down 2, doubled, for -300—losing FOUR spade tricks, one heart, and two clubs.
The full hand was:
Matthew Kidd's thoughts: my first thought was to raise to 3♥ with the East hand, given the diamond shortness, and the fact that dummy's trump are small such that ruffing with them will not promote a trick for the defense. Against vulnerable opponents I like the double because setting the contract at least one for the magic +200 seems very likely. Against non-vulnerable opponents I would only double when playing with a strong partner and when I felt on my A game. Double dummy 1NT* collects +300 while 3♥ collects +140. But dropping a trick on defense will only collect +100.
It's not easy to defend (and play) doubled two level contracts double dummy. On the line above, cashing the ♠A at trick two costs a trick but declarer gave it back by leading to the ♦K at trick four. If instead declarer takes her lumps by leading high trump at trick four, the ♠K followed by the ♠J, North is reduced to the ♠97 over declarer's ♠108, and can take only a natural trump trick or a diamond ruff BUT not both and the defense collects only +100.
There are psychological considerations too. Some declarers get nervous when doubled. Others are steely-eyed and make the most of the information revealed by the double. Know your opponents.
North: ♠987 ♥KQ63 ♦AJ4 ♣K103
South: ♠AK5 ♥AJ1098 ♦95 ♣A92
South is Declarer at 4♥. If you get a low diamond lead, you can duck to the ♦Q (thanks to the power of the ♦9 spot in your hand) and finesse West out of the ♦K later for a spade discard. However, if you get a passive trump or the ♠6 lead, you have to do a little work. Note that the club position (with 10 on one side and 9 on the other) is a classic end play layout—if you can get the opponents to break the clubs for you. So, pull two rounds of trumps, observing the suit to split 2-2. Duck a diamond to the ♦J, which loses. Win the spade return. Play the ♦A, and ruff the third round of diamonds in the South hand, eliminating the suit.
Now, the opponents have no more trumps, and you and Dummy have no more diamonds. Give the opponents the third round of spades—an evenly divided suit between you and Dummy. Poor East has to either lead a spade for a ruff-and-sluff (so a club loser goes away), or break clubs for you. It is correct to play for split honors in the club suit, so you end up losing NO club tricks.
Unfortunately, with a diamond lead against no trump, it makes 5NT easily. South opened 1NT to avoid the rebid problem with 16 HCP, but North elected to try Stayman with a 3-4-3-3 hand. With no ruffing value in the North hand, 3NT is a superior bid. Also, Grant Baze's rule is that if you and your partner have 28 or more HCP, it will often make as much in no trump (on sheer power) as in an 8-card fit. (North does not know it is actually a 9-card fit.) So, in matchpoints, be greedy and try 3NT.