LEARNING CENTER

Duck. This play actually has a fancy name--the Bath Coup (named for the city where whist originated, not the tub). If you win this trick, you are at the mercy of whichever hand has the A. If you duck, then the opening leader has no way of hurting you. 

Win. Here you have spades double stopped if you win the first trick. If you lose the first trick and the opening leader switches to a club, you might find yourself in trouble later. Why did they lead the K? I don't know, maybe the J was hidden with the spades. 

Duck. This is a classic holdup play. You need diamond tricks, so when you lose the lead to the A, you hope the hand that wins has no spades left. To do that, you duck twice. 

Win. When the opening lead is made, it is important to pay attention to the "spots". Here, the 4 could be a fourth-best from four or five or lowest from three. If it were from five, you might hold up a round, but you can tell it's not. The only cards lower are the 3 and the 2, and since you can see those, you know that this is the lowest card the opening leader holds. If you duck, the opponents might switch to clubs. 

Duck. Here, you know you cannot break up your opponents communication, so it doesn't seem like there's a benefit to ducking. I often see newer players just claim "1 spade, 2 hearts, six diamonds and two clubs- Making 5", but at duplicate scoring, every trick counts. While you won't risk a finesse (going down is bad at every form of scoring), you can put the opponents under extreme pressure by ducking the first trick. Look what happens to the West hand below: 

Vul: Dir:	54  AJ10  AKQJ42  K9
QJ104  Q52  987  Q65		K9832  9876  --  10872
	A6  K43  10762  AJ43

If you duck the first trick, and then run all your diamonds, this is the end position

Vul: Dir:	AJ10  2  K9
Q52    Q65
	K43    AJ4

You now play your last diamond, pitching a heart from your hand and what can West do? Now when you play your A and K you'll see one of the queens appear. If you simply took the first trick, you'll only take the 11 you started with. 

Win. People get into habits of seeing a suit like "Axx opposite xx" and they duck before thinking. Here, if hearts behave (3-2 or 4-1 onside) then you'll take 13 tricks--2 spades, 5 hearts, a diamond and 5 clubs. Maybe I should've added a fourth rule, "Don't duck if you have all the tricks."

p.s. After winning the diamond, run the clubs first pitching diamonds. If the hearts do happen to break poorly, the person with four of them might not realize to keep them.