Does a negative double of 1 after partner opens 1 show both majors?
The standard treatment is that a negative double of 1 after partner opens 1 shows both majors, usually 4-4. Longer and unequal lengths such as 5-4 or 4-5 are possible with a weak hand.
Here is why the double needs to be both majors: Due to the way Bridge scoring works, it is extremely important to find your eight-card major suit fits. In a competitive auction you need to do this as quickly as possible. This means that if you have only one major, even if it is only four-cards long, you must bid it right away so partner knows which one you have. When the opponents overcall 1, you can use a negative double to show four spades and bid 1 to show five because, unlike after a 1 overcall, there is no ambiguity as to which major your side holds.
Ask your partner how they would feel looking at a 2-4-3-4 pattern after these auctions if the negative double promised only one (unknown) major :
1 1 Doblo 2
1 1 Doblo 3
You can make a negative double with …Click here to continue reading