Gerber convention
noun
Ger·ber convention
ˈgərbər-
: a bidding method in contract bridge that is based on the Blackwood convention and that uses a bid of four clubs instead of four no-trump as the asking bid, with responses of four diamonds to show no ace, four hearts one ace, four spades two aces, four no-trump three aces, and five clubs four aces
Word History
Etymology
after John Gerber, 20th century American who devised it