Eight Card Brainwave
A spectator is given a free choice from eight face-up cards and it's place aside. The remaining cards are turned over to show that they all have blue backs. The spectator turns over their card and it's the only one with a different colored red back.
His marketed version entitled Eight Card Brainwave with eight cards (1974) was reprinted in The Card Magic of Nick Trost (1997).
- See also: Brainwave Deck.