After one no-trump, have an inquiry

Marcus Tullius Cicero, a Roman statesman, lawyer and orator who died in 43 B.C., said, "It is a shameful thing to be weary of inquiry when what we search for is excellent."

We have various inquiry bids, the best-known being Blackwood and Stayman. Also useful is New Minor Forcing. If the auction starts one of a minor - one of a major - one no-trump, responder's rebid of two of the unbid minor promises at least game-invitational values and asks opener to describe his hand further. Opener's priority is to indicate three-card support for responder's major. Without that, he shows four cards in the unbid major, or usually continues with two diamonds or two no-trump.

In this deal, South answers two clubs with two hearts, showing a doubleton spade and four hearts. When North supports diamonds, which is game-forcing (no stopping on dimes), South, without a club stopper or honor-doubleton in spades, continues with three hearts. North now knows that his singleton club is excellent. It is effectively a 34-point deck (10 points in each of three suits and 4 for the club ace). To make a small slam, you typically need 33 out of 40 points; using this ratio gives 28 out of 34. So, North uses (Roman Key Card) Blackwood and puts South into six diamonds.