Slam Bidding

Decision #1:  Do you have enough overall strength?

When considering a slam, you have to first decide if your two hands have the power to take 12 or 13 tricks once you get the lead. You can often add your points to the number partner has shown to determine your chances. For "normal", fairly balanced hands, use these guidelines: You may make a slam with fewer points if your hands have other features to make up for what you lack in high-card strength. These include:

Decision #2:  Do you have enough controls?

Your second concern is having enough "controls" -- aces, kings, singletons and voids -- to prevent the opponents from cashing two quick tricks. To bid and make a slam, your two hands must have:

Depending on the situation, you can use Blackwood (to ask for aces after a suit bid), Gerber (to ask for aces after a notrump bid), or Cuebids (to find aces when Blackwood can't be used). 

The Blackwood Convention -- 4NT to ask for aces

After you and partner have agreed on a trump suit, a bid of 4NT is the Blackwood Convention, which asks partner to tell you how many aces he holds. Partner responds with a 5-level bid that shows the exact number of aces in his hand. The meanings of his responses are: If two aces are missing --"sign off" in 5 of your suit (or pass, if that was partner's Blackwood response). If your agreed trump suit is clubs or diamonds and you want to sign off in 5NT, bid 5S. This tells partner to bid 5NT, and you will pass.

If only one ace is missing -- you can bid six of your suit or 6NT.

If your side holds all four aces -- and if you think you may have the power to take all the tricks -- you can try for a grand slam by bidding 5NT to ask for kings. Your 5NT bid guarantees that your side holds all four aces and asks partner how many kings he holds. Partner will respond at the 6-level (using the same steps as above) to show the number of kings he holds -- 6C to show none or four kings, 6D to show one, etc.).

The Gerber Convention -- 4C to ask for aces

The Gerber 4C Convention is used to ask for aces after partner opens 1NT or 2NT, or after he opens one of a suit and shows a specific point range by rebidding 1NT or 2NT. In these specific situations, a jump to 4NT would not be Blackwood -- it's a natural raise of notrump that invites partner to bid 6NT if he's at the top of his point range. Partner can pass 4NT if he has a minimum notrump opener or rebid.

A bid of 4C directly over partner's notrump bid is Gerber and asks for aces. Partner's response tells you how many aces he holds:

If your side holds all four aces and you want to investigate a grand slam, a bid of 5C guarantees you have all four aces and asks for kings (just like a rebid of 5NT after Blackwood 4NT). Partner will respond at the 5-level (using the same steps as above) to show the number of kings he holds (5D to show none or four kings, 5H to show one, etc.) .

General Guidelines for Using Blackwood & Gerber

Don't chicken out if you find you have only 3 aces. In most cases, if you don't have enough strength to bid a slam missing only one ace, then you shouldn't be asking for aces.

Remember that Blackwood and Gerber tell you only the number of aces partner has. They don't tell you which suits they're in or whether you're off a cashing Ace-King in a suit. You should only use Blackwood or Gerber when:

  1. You've already found a good a trump suit (or agreed on notrump).
  2. You know you have the overall strength for a slam.
  3. Your hand has controls in all unbid suits (aces, kings or singletons).
DON'T use Blackwood or Gerber if:
1.   You have a void.
2.   You have a worthless doubleton (xx, Qx, Jx) in an unbid suit.
3.   You need to know if partner has control of a specific suit. To get this information, use a cuebidding sequence instead.

The Cuebid -- to find specific aces

For hands where you can't use Blackwood, you can investigate slam by "cuebidding"--bidding new suits to show outside aces. Once you and partner have agreed on a trump suit, a new-suit bid is not a search for a different trump suit. It is a shows a specific outside ace and is a move toward slam in the suit you've already chosen.

Once you and partner have agreed on a trump suit, a new-suit bid by you shows a suit where you hold an ace. It asks partner to cooperate by bidding a suit where he holds an ace. To save bidding room when you're cuebidding, both partners should always bid the cheapest suit in which they have a control (an ace or a void). You can also continue the cuebidding sequence to find a second-round control (the king or a singleton). Here's an example:

S-AK874  H-Void  D-Q43  C-AKJ103

You open 1S and partner bids 3S (a limit raise with 4 trumps). You want to play in 6S if partner has control of diamonds, but you can't get this information with Blackwood (if you bid 4NT and partner answers one ace, you won't know whether it's in hearts or diamonds). To locate the diamond ace, you must start a cuebidding sequence with 4C to show your club ace and ask partner to cuebid his cheapest ace (if he has no aces, he'll retreat to 4S). 

If partner cuebids 4D, you'll know he has the diamond ace and you can bid 6S. If he instead cuebids 4H, it tells you he has the heart ace but not the diamond ace (since he will cuebid his cheapest ace). 

Over partner's 4H cuebid, you can sign off in 4S if you are no longer interested in a slam, but this hand is strong enough to continue the investigation. A 5C cuebid by you shows a second-round control of clubs (king or a singleton) and asks partner to tell you more. Since partner's 4H cuebid already denied the diamond ace, he can now cuebid 5D to show you a second-round control. If he bids 5D, you'll bid 6S. If he bids 5H (showing second-round control of hearts but not diamonds), you'll sign off in 5S. If he bids 5S (showing neither control), you'll pass.