It is a disaster if the matchpoints lost in a sacrifice are more than the points that would have been won by the opposition in making their contract. A bottom score is almost assured.

So knowing the probability of successfully sacrificing is vital, and an important effect on the probability is the vulnerability.

Vulnerability in duplicate bridge is a scoring arrangement that allocates higher scores to some bridge partnerships in an organised pattern.

Vulnerable pairs win more matchpoints when they are successful in game contracts, but they also lose more matchpoints for undertricks in failing contracts.

It is almost always inadvisable to sacrifice when vulnerability is unfavourable (your pair is vulnerable and the opposition is not).

Suppose you hold something like S 3; H AQJ92; D 632; C KQ75; and the bidding proceeds: You 1H; Opposition X (1); Partner 2H (2); Opposition 4S (3).

(1 Opening hand, 4 spades, shortage in hearts; 2. 3 hearts, 6 to 9 points; 3. At least 4 spades, and has points or shape to make game.)

Should you sacrifice?

Not if vulnerability is unfavourable.

You would be required to bid 5H and would probably fail by two or three tricks. When doubled, you would give the opposition 500 or 800 matchpoints when they can only make 420 for a successful game contract.

If the vulnerability is favourable (they are, you aren't), then you should sacrifice.

You will give the opposition only 100 or 300 matchpoints from your doubled, failed contract, when they will probably earn 620 for making a game in spades. 

If the vulnerability is equal, it is less obvious, but probably inadvisable to sacrifice.

All clear?  Who said bridge is an easy game?

CONGRATULATIONS to all those Bathurst Bridge players who recently won tournaments in both the outright and handicap categories.

They include Col Kleinig, Jane Stephens, Allan Adcroft, Bill Kierath, Val Irvine, Irene Faulkner, Anne Elliott, Pam Stuart-Brown, Anne Hunter, Phil Cummings, Dick Ellis, Alan Sims, Jim Driscoll, Elaine Walker and Nora Taylor.