Rosenkranz double
Encyclopedia
The Rosenkranz double and Rosenkranz redouble
are elements of a bridge
bidding convention
invented by Dr. George Rosenkranz
, collectively known as the Rosenkranz double
. The calls are made by the partner of an overcaller (the advancer) to describe his top honor card holdings in the overcaller’s suit.
(i.e. not a ‘Pass’) by the opener’s partner (the responder). Three cases follow: (1) if responder made a bid below two of opener's suit, a ‘double’ by the advancer is a raise of the overcaller’s suit and promises a top honor; (2) likewise, if opener’s partner doubles the overcall, a ‘redouble’ by the advancer has the same meaning; but (3) if, instead, the advancer makes a raise to the two-level in overcaller’s suit, he denies possession of a top honor in that suit. A top honor is either the Ace, King or Queen.
Showing the top honor may allow the overcaller with a serrated holding to lead the suit safely; while denying the top honor (and thereby suggesting strength elsewhere) encourages the overcaller to lead a different suit.
The use of this convention would be inconsistent with Responsive Doubles.
The reasoning for the reverse treatment is that a better hand for the bid suit (by virtue of the additional honor strength) should raise the level of the auction to make things difficult for the opponents.
The Rosencranz redouble is also used to indicate an honor doubleton in overcaller's suit.
The Snapdragon convention is a double by advancer when three different suits have been shown by the other three players, and nobody has jumped. It shows length in the fourth (unbid) suit, and tolerance for partner's suit (10x or better).
Rosenkranz redouble
The Rosenkranz double and Rosenkranz redouble are elements of a bridge bidding convention invented by Dr. George Rosenkranz, collectively known as the Rosenkranz double. The calls are made by the partner of an overcaller to describe his top honor card holdings in the overcaller’s suit....
are elements of a bridge
Contract bridge
Contract bridge, usually known simply as bridge, is a trick-taking card game using a standard deck of 52 playing cards played by four players in two competing partnerships with partners sitting opposite each other around a small table...
bidding convention
Bridge convention
A bridge convention is a system of calls made during the auction phase of a contract bridge game which conveys a coded meaning about the players' card holdings...
invented by Dr. George Rosenkranz
George Rosenkranz
George Rosenkranz is a Mexican scientist in steroid research and a professional bridge player. He was born in Hungary, educated in Switzerland and lived in Mexico for 66 years...
, collectively known as the Rosenkranz double
Rosenkranz double
The Rosenkranz double and Rosenkranz redouble are elements of a bridge bidding convention invented by Dr. George Rosenkranz, collectively known as the Rosenkranz double...
. The calls are made by the partner of an overcaller (the advancer) to describe his top honor card holdings in the overcaller’s suit.
Original version
The conventions come into play when the auction has started with: (a) an opening bid by the opponents; (b) a direct overcall by partner at the one-level; and (c) a bid or negative doubleNegative double
The negative double is a form of take-out double in bridge. It is made by the responder after his right-hand opponent overcalls on the first round of bidding, and is used to show both support for the unbid suits as well as some values. It is treated as forcing, but not unconditionally so...
(i.e. not a ‘Pass’) by the opener’s partner (the responder). Three cases follow: (1) if responder made a bid below two of opener's suit, a ‘double’ by the advancer is a raise of the overcaller’s suit and promises a top honor; (2) likewise, if opener’s partner doubles the overcall, a ‘redouble’ by the advancer has the same meaning; but (3) if, instead, the advancer makes a raise to the two-level in overcaller’s suit, he denies possession of a top honor in that suit. A top honor is either the Ace, King or Queen.
Showing the top honor may allow the overcaller with a serrated holding to lead the suit safely; while denying the top honor (and thereby suggesting strength elsewhere) encourages the overcaller to lead a different suit.
The use of this convention would be inconsistent with Responsive Doubles.
Reverse Rosenkranz
Subsequent to creating the Rosenkranz double and redouble, Rosenkranz announced in a letter published in the ACBL's Bridge Bulletin that he had adopted a proposal by Eddie Wold to switch the meaning of the two sequences, so that the advancer's immediate raise now showed the Ace, King or Queen honor, while the double (and redouble) denied it - a treatment known as "Reverse Rosenkranz". The term "Guildenstern" (a reference to Shakespeare's other courtier in the play Hamlet) is also used for these sequences in independent creation of "Reverse Rosenkranz".The reasoning for the reverse treatment is that a better hand for the bid suit (by virtue of the additional honor strength) should raise the level of the auction to make things difficult for the opponents.
Variations
Munson, created by Kitty Munson Cooper, (or sometimes, "Tolerance Redoubles") in which the redouble shows shortness (one or two cards) including the ace or king. After a Munson redouble, the overcaller's spot-card lead in his overcalled suit is suit preference for the side suit to shift to.The Rosencranz redouble is also used to indicate an honor doubleton in overcaller's suit.
The Snapdragon convention is a double by advancer when three different suits have been shown by the other three players, and nobody has jumped. It shows length in the fourth (unbid) suit, and tolerance for partner's suit (10x or better).