Keep this safely in your folder so that you can refer back to it.

Let's look at the following table:

You have just been dealt a hand like this:	6
	A 7
	Q J 9
	A K 10 8 6 4 2

You are in the situation "not vulnerable" against "vulnerable"; your opponents bid a contract of 4…

You ask for your partner's little paper and read: (3, 4, 3, 3)

You calculate that you have 22 DH points and particularly a good chance of making eight tricks in Clubs (with ten cards in your side).

Let's suppose that you bid a contract of 5. It is almost certain that:

Yes, but … if you manage to make the probable eight tricks, you will have a "bill" of three down to settle; looking at the table above, you will realise that this will only cost you 500 whereas if your opponents make the contract of 4, they will score 60 … And it is more or less certain that the contract will succeed since you can hardly hope to make one Club trick (and the rest …) and the Ace of Hearts. As for your partner, he can't have many tricks with his 3 points …

So, in such a case, when you have the double certainty that the opponent is going to make his contract and that you will only fail by a small margin, you make a bid called a defence or sacrifice bid. The objective of Bridge is in fact to make the best score or, which amounts to the same thing, to let the opponents score as little as possible.

But, to achieve this, you must be certain that you are undertaking a good operation; you will therefore avoid doing it if you are vulnerable against not vulnerable because two down doubled will cost 500 points whereas the opponents' game call will only make 420 or 400; it's the same thing if you risk going three down not vulnerable (500) against a vulnerable game call … Sometimes it would be just as stupid if the wonderful game bid by the opponent were unwinnable …!