Slam Bidding & Blackwood


Slam Bidding & Blackwood

Bidding to small slam (the 6 level), or grand slam (the 7 level) is exciting. Before committing to such a high level, the partnership needs to check whether they have:

  • enough power
  • what to play in (a suit or no trumps), and
  • controls

You need 33 points for a small slam, and 37 points for a grand slam. With two balanced hands, it's all about points, but there's more to consider when there's a fit. In either case, it would be embarrassing to reach slam and have the opponents take the Ace and King of a suit against you when they make their lead.   

Once you've found a trump fit, check for controls  (A control is a card that stops the opponents taking too many tricks in a suit). The ace (or void) is a first-round control, since it stops the opponents from taking the first trick. A king (or singleton) is a second-round control. The opponents can take the first trick in the suit with their ace, but the king (or singleton) will stop them on the second round. 

Before going to slam you need first-round control of at least three suits. One way for the partnership to be sure they are not missing too many controls is to use the Blackwood convention after a trump suit has been agreed. This convention was designed to keep partnerships out of bad slams by helping them discover if they were missing too many controls. It's not suitable for all situations.  

Blackwood is 4NT, only when it is clear the partnership has found a fit, and is considering going further than game. It's an artificial bid asking  partner how many aces they hold. The responses are:

5♣ =  No aces
5♦ =  One ace
5♥ = Two aces
5♠ = Three aces

If you discover that the partnership holds all the aces, 5NT next asks about kings.NB: don't ask for kings if the partnership does not hold all four aces.  

6♣ =  No kings
6♦ =  One king
6♥ = Two kings
6♠ = Three kings

Once you're familiar with Blackwood, there's a more advanced version which gives more info. That's Roman Key Card Blackwood. (Don't try this if you're a new player).   

Key Card Blackwood acknowledges that the king of the trump suit is as important as an ace for bidding suit slams. If a king in a side suit is missing, it might be possible to avoid a loser. But, If the king of the trump suit is missing, it’s a different story. So, Key Card Blackwood includes the trump king in the answers, so think of the king of the trump suit as if it were an ace, and instead of four key cards (the four aces), you now have five (the fours aces and the trip king).  It's also possible to discover whether the partnership also holds the trump queen.  
These are the responses when using Key Card Blackwood: It's called fourteen thirty "1430" (which is also the score for a small slam in a major!) 
5♣ = One or four key cards  (14)
5♦ = Zero or three key cards (30)
5♥ = Two key cards (or all five) without the queen of trumps
5♠= Two key cards (or all five) with the queen of trumps

There's a little more to it after that, but it's not necessary now. The main point about any version of Blackwood is that it will only tell you the number of aces that are missing. It won't tell you which aces.  (For which aces, wait until next week!)


Looking for more information? These books will help you learn the basic skills required to play bridge. 

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