A while back someone posted an explanation of a mind-reading double act that had fooled the experts. These demonstrations in which the audience put random items onto a tray and then the "sender" asks the "receiver" what he's holding and she's able to tell us usually involve a simple code. What made this act so baffling was that the performer was using the "one-ahead" routine. It would be agreed before the show that the first item held up that night would be a credit card. The coded message used by the sender would refer to the *next* item he was going to pick up and not the one he was actually holding aloft. Geddit? Simple but effective.
That routine really tickled me. However I've now come across another method that also left the experts at a loss. Sam Loyd (Yank - 19th century) used to do a routine in which he would blindfold his son and have him stand with his back to the audience. A legit deck of cards would be shuffled by an audience member (not a stooge) who would then hold up each card in turn for Sam Loyd to see. Lloyd would gaze at the card and not say a word or move a muscle and eventually his son would announce "Ace of Hearts" and be correct. This would continue through the pack. So how was it done? Think about it and see if you can work it out. The solution is . . . Have your tiny brains worked it out yet? Awesomely simple . . . And it is? The son never spoke a word! Sam Loyd was a ventriloquist!