User:Brian/Bridge/Responding to Blackwood
When partner has bid 4NT and according to your partnership agreements, your partner's 4NT bid means Blackwood, you must first remember which suit has been agreed upon as trumps, then respond to show how many keycards you hold. There are five keycards in total: the four aces, and the king of trumps.
Figuring out which suit is the trump suit
If you opened with notrump, make sure the 4NT bid is not a quantitative raise. If it's a quantitative raise, then it's not Blackwood!
If suit agreement has already been established, the agreed suit is the trump suit your partner is asking about. You need to know which suit is trumps so you know which suit's king to count when you make your response.
- If partner bid a suit and you supported it by bidding the same suit, then that suit is trumps. The same goes if you bid a suit and partner supported it.
- If you or your partner bid a suit and the other made a conventional raise, then that suit is trumps. For example, if your partner opened 1♥ and you responded with Jacoby 2NT, then hearts are trumps. If you opened 1♠ and partner responded 4♦—a splinter—then spades was agreed as trumps.
- If suit agreement was established by the initiation of control bidding by either you or your partner, then the suit previously agreed is still the trump suit.
- If agreement has not been shown, double-check that 4NT isn't quantitative before proceeding! It's quantitative if you opened notrump. (2♣ - 2♦ - 2NT and 2♣ - 2♦ - 3NT count as opening notrump.)
- If agreement has not been shown, but you're sure that 4NT is, in fact, Blackwood, then partner is implicitly agreeing with the last bid suit.
Responses to Blackwood
| If... | then... |
|---|---|
| I have 0 or 3 keycards | Respond 5♦. |
| I have 1 or 4 keycards | Respond 5♣. |
| I have 2 or 5 keycards, but I don't have the queen of trumps | Respond 5♥. |
| I have 2 or 5 keycards as well as the queen of trumps | Respond 5♠. |
Subsequent bidding
| If... | then... |
|---|---|
| Partner rebid the trump suit | Pass; partner has placed the contract. |
| Partner bid the next step up, but still below 5 of the trump suit | Partner is asking for the queen; respond accordingly. |
| Partner bid 5NT | Partner has concluded that together you hold all five keycards and the queen of trumps, and is now asking for kings. Respond accordingly. |
| Partner bid 6NT or 7NT | Pass. This is to play. |
Although usually the contract will be a suit contract, partner may sometimes conclude that 6NT or 7NT is likely to make and is a better contract. The 10 point bonus is significant at matchpoint scoring, and the danger of opponents getting in a ruff is eliminated.
