To ignore an already identified ace (such as by a cue bid) in responding to Blackwood. This convention is now rare as many pairs cue bid both first- and second-round controls and so need 4NT to identify which is which.
To ignore an already identified ace (such as by a cue bid) in responding to Blackwood. This convention is now rare as many pairs cue bid both first- and second-round controls and so need 4NT to identify which is which.