The Origins of Wonder
The principle that a spectator tends to shuffle the top card to the bottom in a single Overhand Shuffle of a small packet of cards was discovered by John S. Frazee and published as “The Shuffle Force” in The Linking Ring, Vol. 26 No. 2, Apr. 1946, p. 56.
It was popularized by Ed Marlo, who described it in Estimation, 1962, p. 33, but didn't recall the exact reference, writing only the following at the end of the description: “To my knowledge, the only place this 'top card to bottom' in an Overhand Shuffle idea appeared was many years ago in the LINKING RING”.