relknes, on 2011-December-15, 11:02, said:
So what would you do if you have, say, diamonds and hearts, but not clubs?
This is where it doesn't work, when both parties are unlimited by the bidding. However, often somebody makes a bid which limits the hand to a range of values. In that case, it is easy.
Example : 1♠ 3♦ (Bergen 4 card support bid, defined strength/HCP range) 3NT.
We play non-serious (or frivolous) 3NT, where it is 3NT over spades, but 3♠ over hearts. So when both sides are undefined in strength, a serious hand would bypass that bid and make a cue bid. However, if partner is limited, as in this example, there is absolutely no sense in telling him you, too, are limited; you just sign off in game. So now the 3NT bid becomes a "serious 3NT", which insists on a cue bid sequence. However, this bid denies control in clubs. If you had club control, but not diamonds, you would have bid 4♣, the one beneath the one you want partner to bid. So you can in fact ask for the cheapest.
Most times, in fact, one partner has limited his hand in some way. In a 2 over 1 sequence (the way we play it) opener limits his hand if his initial rebid is no higher than 2M (2NT from responder then asks for shape).
Where both are unlimited, partner has bid 3♠ agreeing trumps in a forcing situation, and we are serious with missing club control, at the moment we just bid as if we have it, and take a risk, if you like, of missing the top 2 tricks in the suit. But this is the only suit with a problem, and we think it worth the definite advantage of always being able to show extra strength (without being unilateral), to enable partner to bid on if he too has extra strength. The "16 points opposite 16" hands (or equivalent) is a bigger problem otherwise.