Negative Doubles

After an Opening of 1 of a minor and subsequent Overcall, Responder doubles to show other suitedness.

Opener
Overcaller
Responder
Doesn't matter, just filling a chair, like dummy sort of
1
1
X*

Whatever

Responder shows at least 4 cards in each remaining suit, hearts and spades here, and 6+ points. Kxxx Kxxx xxx xx or AKQJ AKQJ x xxxx

Opener
Overcaller
Responder
Doesn't matter, just filling a chair, like dummy sort of
1
1
X*

Whatever

Responder shows at least 4 cards in each remaining suit, hearts and clubs here, and 7+ points. xxx Kxxx xx KJxx or xxxx AKQJ x AKQJ

Most advanced partnerships prefer the negative double to show ONLY an unbid major (when one major, the other one, has been bid).
xxx Kxxx xxxx KJ or QJxx AKQJ xxx AK

Rational: - As qualification requirements decrease, frequency of occurence increases.
- More major suit contracts, including partials, are declared in major suits than minors.

Overcallers skip levels of bidding

Opener
Overcaller
Responder
Doesn't matter, just filling a chair, like dummy sort of
1
2
X*

Whatever

Responder shows 4 spades, the other major (unbid).
The point requirements for negative doubles increases depending on how high Opener will have to rebid after the NOT PENALTY ORIENTED double.

1 1 X P
?
Opener can rebid as sho

 

xxx Kxxx xx KJxx or xxxx AKQJ x AKQJ