Gerber
The use of 4
to ask for aces. If
partner’s last bid was a natural bid of 1NT or 2NT,
then a jump to 4 is Gerber. The responses are:
4 |
shows zero or all four aces |
4 |
shows one ace |
4 |
shows two aces |
| 4NT | shows three aces |
See also Defence to Blackwood Interference.