.

You have all three side suits well controlled. Declarer will not be able to set up or use any tricks in dummy for discards. The only possible thing he can do with losers is trump them in dummy. He appears to have small diamonds (maybe 4 of them if partner’s 2 shows an odd number of diamonds—count). He wants to trump diamonds in dummy and you want to stop him. Shift to a trump. Whether or not declarer takes the ace now, your partner will get in with his A and continue trumps. Declarer will be unable to ruff any diamonds in dummy and will finish down 1. Without your trump shift, declarer would make the contract—getting to trump a diamond in dummy.

Vul:BOTH Dir: SOUTH	AQ2 K432  65  AK53
4  QJ109  KJ109  QJ107		K53  865  AQ2  8642
	J109876 A7  8743  9

. Make the aggressive switch to a low diamond. Declarer (from the bidding) has 6 spade tricks. From the Q lead, you place declarer with the AK. Once you take your K, dummy has 3 good clubs. Declarer has 6+2+3=11 tricks you know of. If he also has the A, he has the rest. Your only hope is partner has the A. The full deal:

Vul: Dir:	A97  543  Q96  AQJ8
5  QJ1092  A32  7542		632  876  KJ87  K96
	KQJ1084  AK  1054  103

. Go passive. Return a heart. Declarer has 6 spade tricks, the A, and A. He might (probably) have the A, too, for 9 tricks. There is no source of tricks/discards in dummy. Don’t even dream of switching to diamonds. The full deal:

Vul: Dir:	A97  543  Q96  AQ86
5  KQJ102  108732  105		632  987  KJ5  KJ94
	KQJ1084  A6  A4  732

2.

You should shift to an aggressive, attacking low heart. Why? Declarer likely has 6 spade tricks. If you go passive, he will play clubs, knocking out partner’s A. That will bring his total to 11 tricks (6 spades, 3 clubs, A and K). If declarer has any hearts to lose, you must play one now while partner still has the A. You hope partner has the Q. If declarer has it, there is nothing you can ever do. As you can see, your heart shift sets the contract. Partner puts up the queen and declarer must eventually lose 2 heart tricks in addition to the 2 minor-suit aces.

Vul:Both Dir: South	KQ4  AJ96  75  KQJ10
87  Q84  QJ1094  A75		63  K102  A832  9632
	AJ10952  753  K6  84

.

This situation screams for passivity. In fact, I think an original trump opening lead is sensible. Now that you’ve led the A and seen the 6, what do you know about the hearts? Partner’s 6 is the lowest spot card so he is discouraging (more on this in Larry Teaches Defense or on the DVD about signals). Partner does not have the Q (or a doubleton). Do not continue the suit, because it could easily look like it does below. A minor-suit switch is dangerous (just look at the harm done by the J or a club switch). Those minor suits are like most suits—he who breaks the suit loses. There is no source of tricks in dummy. No need for aggression. The safe play is a trump. After that, declarer has to do his own dirty work. In the goodness of time, he will likely lose 3 hearts, 2 diamonds, and 1 club.

Vul:Both Dir: South	KQ4  543  K92  J974
832  AK10  J106  Q1082		97  J876  A843  K63
	AJ1065  Q92  Q75  A5

. You know declarer showed 20 or 21 points and dummy has 10 points for 30 points for the opponents. You hold 11. That means partner has zilch (and that declarer chose to open 2NT with 19, as some will do). Yes, you are going to have to pitch a bunch on the diamonds, but you get to pitch after declarer. You can start throwing any suit declarer throws away the jack in. In the meantime, you'll pitch one club and then a heart.

After your defense, partner will offer a likely "I knew we had it beat". The full deal:

Vul: Dlr:	54  A3  KQJ1095  1098
Q109  QJ109  A4  Q532		8762  8762  32  764
	AKJ3  K54  876  AKJ