The Forcing Game
Dink. Pump. Force. They all mean you're "forcing" declarer to shorten his trump holding (in the long hand, by and large), perhaps to the same number as one of the defenders holds while a key card still needs to be knocked out, perhaps even to fewer than one of the defenders. I put "forcing" in quotation marks because it's not altogether mandatory for declarer to ruff. But when he declines, you're getting that trick (we're presuming that you are leading high side-suit cards). Consider this situation, spades trump, the clubs having all been played:
|
 ----- |
|  8 7 | |
|  7 6 |
| 7 6 |
|
------ |
|
| ------ | |
6 5 4 |
| Q J | |
5 |
| 10 8 |
|
A K |
|
------ |
| |
How many of the remaining tricks can declarer pick up, and how many the defense? Well, of course it depends upon who's on lead. If declarer's on lead, he simply runs his top trump and then two hearts. But if West's on lead? He leads a top diamond, forcing declarer to ruff. And declarer is trapped. If he tries to cash a heart, West ruffs and forces declarer again in diamonds, getting two of those four tricks. Declarer does no better to draw one round of trump before trying to cash a heart. He would then be out of trump, while West would hold the last trump and the high diamond.
In play the opportunity doesn't always or even often surface in such an apple-pie order. That was just to illustrate what a force was all about and how it benefits the defense if feasible. In play, you might have K 7 6 5 in trump back of a declarer with a 5-card suit headed by the A Q J. If your side has a good suit with, say, 3 cards in dummy, and declarer a singleton, two leads brings his down to the same length as yours, and you've got the K! The third round of your suit, after winning with the K of trump, may prove very inconvenient to declarer.
To be sure, when we come to four suits, there are often strategies declarer can resort to in order to obviate the damage. On the third round, he might sluff a loser and then be able to handle a fourth round with a trump in dummy, and thus be in a position to draw your trump. Or if he has, say, the 10 9 of trump in dummy, he might just say (if he has the right distribution), "Okay, I'll just crossruff out the hand. Thanks for giving me that opportunity to ruff your suit a second time."
It's not going to work when declarer is loaded for bear in trump (though forcing him to ruff might be a safe lead), and also is not too likely to work on a 4-4 fit, if declarer has some good honors in dummy, for declarer might welcome repeated ruffs, and play the hand from dummy. However, it could work not so much on length as strength: if declarer has the top four trump in the closed hand and a 9-high 4 spot cards in dummy, then two forcing leads would establish a twice-guarded 10. (Though to be sure, declarer might decline to ruff a second time for that reason. But if so, you get that side-suit trick.)
This is not the most common of defensive opportunities. Failing to exploit a forcing defense is not on a par for lost tricks covered in many other categories. Four-Card Holdings and Covering an Honor offer so many instances of tricks thrown away, that I stopped collecting examples years ago. Second Hand Low, Third Hand high? Yes, both more common. Sluff & Ruff? Oh, my yes. Considerably more common. Indeed, when I look at the Defense categories, I would have to say this is one of the stingiest about instances. Still, it's not an either/or situation. It's another strategy for besting your opponent, another addition to your repertory. Since the leads you hope will force declarer to a trump shortage often work at the same time as safe leads, it's an opportunity you don't want to dismiss easily. So I would encourage the reader to keep his eyes peeled.
Neophytes have been known to protest, "Why should I lead that suit when he's just gonna ruff it?" Actually, I can think of three reasons why you might want to lead a suit you know declarer will ruff. One is that you just might get an Uppercut, discussed here. The second is a safe lead, though beware if declarer has a lovely (long) side suit in dummy. Let him ruff and come to your tenace holding. And this is the third. If you've got top cards in the side suits and declarer doesn't have an altogether robust trump suit, the forcing attack just might be your meat.
Above are some links to examples you might wanna ponder.