This family of secret additions loads cards from the top of the deck beneath a small packet, usually fanned or spread, in the opposite hand, through a pivoting action resembling the opening of a book. The first of these add-ons was recorded in “The Case of the Four Kings” by John J. Crimmins, Jr.; see Encyclopedia of Card Tricks, 1938, p. 327. Crimmins didn’t hold the packet fanned or spread, but the dynamic of the add-on is the same one used in later variants that did. The sleight didn’t attract much attention and has been for the most part forgotten.
Edward Marlo contributed a variant handling of this type of addition to Alton Sharpe’s Expert Card Conjuring, 1968, p. 37. His add-on, using a spread packet, inspired a number of variants:
Doug Edwards basically reinvented the sleight, with some handling differences, and published it ten years later in Cardmania, 1978, p. 28. John Mendoza, after studying Marlo’s add-on and Edwards’s, developed another variant in Throwing the Switch, 1982, p. 1. In the same year, John Carney, inspired by Marlo’s addition, published his distinctive version, the Versa Switch in Genii, Vol. 46 No. 10, Oct. 1982, p. 667. Then, in July 1984, Ed Marlo returned to the subject, publishing further variants in The New Tops, Vol. 24 No. 7, July 1984, p. 8. In 1985, Mendoza described Chris Kenner’s handling, based on Mendoza’s, in The Right Stuff, p. 1. More handlings followed.
Also see Scoop Addition