Gerber Ace-Asking 4

4 is used as an ask for Aces. 

The response are:

• 4 shows 0 or 4 aces
• 4 shows 1 ace
• 4 shows 2 aces
• 4NT shows 3 aces

If, and only if, the partnership holds all four Aces, the 4 Club Gerber bidder may next bid 5 Clubs to make a similar inquiry about partner's King holdings.

The king ask is 5 and the responses are:

• 5 shows 0 or 4 kings
• 5 shows 1 king
• 5 shows 2 kings
• 5NT shows 3 kings

Playing Gerber, 4NT is natural and quantitative. In most cases people play Gerber only after a NT opening or a natural NT bid. However, Gerber may be played after any opening or response if the partnership agrees on it.