The Rosenkranz double and Rosenkranz redouble are elements of a

bridge A bridge is a structure built to span a physical obstacle (such as a body of water, valley, road, or rail) without blocking the way underneath. It is constructed for the purpose of providing passage over the obstacle, which is usually somethi ...

bidding

convention Convention may refer to: * Convention (norm), a custom or tradition, a standard of presentation or conduct ** Treaty, an agreement in international law * Convention (meeting), meeting of a (usually large) group of individuals and/or companies in a ...

invented by Dr.

George Rosenkranz George Rosenkranz (born György Rosenkranz; 20 August 1916 – 23 June 2019) was a pioneering Mexican scientist in the field of steroid chemistry, who used native Mexican plant sources as raw materials. He was born in Hungary, studied in Switzerl ...

, collectively known as the Rosenkranz double. It is a made by the (partner of the ) in an auction where opener, overcaller and responder have all bid different suits. It is used to describe the advancer's 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 double The negative double is a form of takeout double in bridge. It is made by the responder after their right-hand opponent overcalls on the first round of bidding, and is used to show shortness in overcall's suit, support for the unbid suits with emphas ...

(that is, not a Pass) by the opener's partner, responder. Two cases follow: (1) if responder bids below two of opener's suit, Double by advancer is a raise of the overcall and promises a top honor; (2) if responder doubles, Redouble by advancer has the same meaning. Either way, advancer's natural raise to the two-level 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.

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 Edward M. "Eddie" Wold (born 1951) is an American professional bridge player from Houston, Texas. Wold is a graduate of Rice University. Wold is an accomplished teacher and plays regularly at Houston's Westside Bridge Academy, particularly in tha ...

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" (alluding to Shakespeare's

Rosencrantz and Guildenstern Rosencrantz and Guildenstern are characters in William Shakespeare's tragedy ''Hamlet''. They are childhood friends of Hamlet, summoned by King Claudius to distract the prince from his apparent madness and if possible to ascertain the cause o ...

) is also used for these sequences, an 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'' (or "Tolerance Redoubles") is an alternative, created by Kitty Munson Cooper, in which the redouble shows shortness (one or two cards) including the ace or king. After a ''Munson'' redouble, overcaller's spot-card lead in his suit is a showing which side suit overcaller prefers partner to lead back (shift). The Rosencranz redouble is also used to indicate a doubleton honor in overcaller's suit.Donald Farwell and Jason Rosenfeld, ''Bridge Baron Companion'', Third Edition, Great Games Products, 2008, , page 186. The Snapdragon double is a convention used by advancer when the other three players have shown three different suits without a jump. It shows length in the fourth (unbid) suit, and tolerance for partner's suit (10x or better).

References

External links

Bridgehands.com: Rosenkranz Double
{{DEFAULTSORT:Rosenkranz Double Bridge conventions