7-0-5-1 Distribution: what to you open?

[shaky44]

All that matters are controls. Bid them up the line (opener bids 5♦ on your example). At some point (usually) opener chooses between 5, 6 and 7 of his suit. NT is almost never an option because of the ambiguity between voids and aces.

 

I guess responder can't really show trump ace in this sequence:

 

S: 4S

N: 5C (indicates club control)

S: 5D (indicates diamond control)

N: 5S??? (probably indicates no further controls to show???)

S: 6S??? (gambling that diamonds will run)

 

 

The 4NT bid to show specific also makes it difficult to figure out which aces partner has on this hand:

 

S: 4NT

N: 5NT (two aces)

S: 6S??? (impossible to know which two aces, plus already gambling that diamonds will run)

 

The 4S opening does have the benefit of finding out if partner has any help in trump.