THE NEW OLD-FASHIONED BIDDING WHEEL

When you know your side has enough points for a slam you may want to
to be sure you are not missing two Aces.
These two conventions will let you ask partner how many Aces (then Kings) he holds.
Blackwood convention uses a 4NT bid to ask, Gerber convention uses 4♣ to ask.

    RESPONSES TO 4NT BLACKWOOD
  • 0 or 4 Aces : bid 5♣
  • 1 Ace : bid 5♦
  • 2 Aces : bid 5♥
  • 3 Aces : bid 5♠
If the partnership has all 4 Aces, then 5NT may be used to ask for Kings.
    RESPONSES TO 5NT BLACKWOOD
  • 0 or 4 Kings : bid 6♣
  • 1 King : bid 6♦
  • 2 Kings : bid 6♥
  • 3 Kings : bid 6♠
    RESPONSES TO 4♣ GERBER
  • 0 or 4 Aces : bid 4♦
  • 1 Ace : bid 4♥
  • 2 Aces : bid 4♠
  • 3 Aces : bid 4NT
If the partnership has all 4 Aces, then 5♣ may be used to ask for Kings.
    RESPONSES TO 5♣ GERBER
  • 0 or 4 Kings : bid 5♦
  • 1 King : bid 5♥
  • 2 Kings : bid 5♠
  • 3 Kings : bid 5NT