In the game of Spade, the Big 5 conventions (invent by Herm Carney and Roger Denino, as stated in a video by Joe Andrews) means that if the first partner bids 5
it signals to the second partner that she can cover a Nil bid. That is to say, if partners play by this convention, the first bidder only bids 5
when she have certain hand that can cover a partner Nil.
I found the exact rules of when to bid 5 are vague. Of course every couple can decide upon a slightly different convention, however I am interested in the original\popular convention.
I play that the first bidder only bids 5 if have:
Ace or King of spade
4 to 6 takes
in each of the side-suits, has one of the following options:
a. Void
b. Singelton higher than {5}
c. Doubleton higher than {5,8}
d. A honor card
My question is, what exactly a 5 bid
by the first partner represent in the big 5 convention?
The vagueness is mostly in section 3 (cover in side suits). Another issue I suspect needs to be defined better: if you only have a single spade (Ace or king) is it still acceptable for a bid of 5?