In this one-handed switch, the top card of the face-down deck is pushed over and the hand turned to display the index of the sidejogged card. During the turn of the hand, the second card is pushed over and the top card is drawn back, so the spectators see the index of the second card instead. When the action is reversed and the top card tabled, the card has been switched.
The switch belongs to Judson Brown and was published as “A One Hand Top Change” in Genii, Vol. 1 No. 12, Aug. 1937, p. 11.
It is often incorrectly credited to Bert Allerton, due to its appearance within Allerton's trick “Magnetic Thought” in More Card Manipulations No. IV, 1941, p. 45, and later as “The Allerton Change” in Hugard's Magic Monthly, Vol. 3 No. 3, Aug. 1945, p. 144.
It shows up even earlier as a very brief entry in Page Wright's Notebook, 1933, p. 13, without further credits. It is described in detail in the posthumously published Page Wright's Manuscript, 1991 (written ca. 1929), p. 112, “A One-Hand Top Change”. Since no other creator is mentioned in Wright's write-up, the sleight has since sometimes been credited to T. Page Wright. This is incorrect, however, as Wright gives credit to Judson Brown in the introduction to his manuscript on p. 8. The 1937 publication in Genii mentioned at the top seems to be an edited extract from this manuscript, in which the Brown credit was added.