S. W. Erdnase (pseudonym, active c. 1902) is the mysterious author of The Expert at the Card Table, a landmark work on card handling, gambling sleights, and deception. First published in 1902, the book is revered for its technical depth and elegant prose. Despite decades of speculation, Erdnase’s true identity remains unknown, adding to the mystique of a work considered essential reading by magicians and card technicians worldwide.