The first published description of the Buckle Count is believed to be within the context of a routine titled “Solo Flight Aces” in Hugard and Braue's Expert Card Technique (1940, see p. 255). This routine combines the Stanley Collins's Ace Vanish with a second sequence using the Buckle Count, credited to Dai Vernon. Nine years later, the Buckle Count was described in another Vernon trick, “Mental Card Miracle”, in Series 5 No. 3 of Stars of Magic (1949). The Buckle Count was also credited to Vernon by Lewis Ganson in Dai Vernon's More Inner Secrets of Card Magic (1960, p. 86), where it is stated that Vernon devised it over thirty years earlier. Vernon also told a number of cardmen, including Edward Marlo, that the Buckle Count was his invention. Curiously, ten years after the Ganson book was published, Vernon contradicted all this. In Dai Vernon's Expanded Lecture Notes (1970, p. 8) the Buckle Count is referred to as the “Six Card Repeat Count” and is credited to John Booth. However, Booth explained in correspondence with Stephen Minch that he used a Push-off, not a buckling action, for his Six-Card Repeat Count. This information is detailed in The Vernon Chronicles, Vol 2, 1988, p. 23. When Vernon was asked, during the taping of the Revelations videos (1982), who invented the Buckle Count, he said he thought it was Elmer Biddle, which is almost surely not correct. At that time, Vernon was around eighty-eight years old and his memory, although admirable, was probably muddled on this point. On other occasions, later in the 1980s, when asked the same question, he simply could not remember.
Bart Whaley, in his Encyclopedic Dictionary of Magic, states that Charlie Miller wrote in the 1930s that he had been taught the Buckle Count by A. J. Cantu. Regrettably, Whaley gives no source for this information. It was likely drawn from correspondence by Miller.
After reading the above information, Max Maven wrote on December 4, 2018: “When the Buckle Count came up in my discussions with the Professor, he did not lay claim to it. Rather, he made it sound like something that made the rounds among the 'inner circle' back in the 1930s—one of those ideas that was the subject of sessioning, without specific knowledge of a source.”
Given the confusion and contradictions summarized above, until further information surfaces, it seems reasonable to leave the originator of the Buckle Count as uncertain. The Block Push-off and Pull-Down sewed the soil for the Buckle Count, and its invention may that been harvested by more than one magician, and the sleight then circulated. The time was ripe for the idea to appear.
For another recounting of the history of this sleight, see Jon Racherbaumer's essay, “What about the Buckle Count?”, in the April 1992 issue of The Olram File (Vol. 1 No. 11, unpaginated).
Also see Buckle