In my reading of The Bat magic magazine, I found an interesting trick from July 1945. In the magazine, this is called Radio Mind Reading by Professor Elkan M Lipka. Despite the name, I’m not sure how this would work over the radio, but the magazine says it’s a good phone trick that makes much more sense.
The effect is you show the layout below. Someone thinks of a any card and they tell you if it’s in row A or B. Then they also tell the which of the numbered rows it’s in. You then tell them the card they are thinking of.
I posted this on my Facebook and had people do it. I did make one change: instead of them telling me which rows it appears in, I had them tell me the sum of the rows. I think that buries the method a little bit by adding a variable where you could get to a number multiple ways.
A change I would make is to adjust the method to match a memorized deck stack rather than the ace-to-king order. That would make it a trick that the average person couldn’t backtrack. That said, in either form, all the person has to do is say it’s math or an algorithm, and they’d be right, and there’s really nothing you can do to dispel that.
I think that if you used this with a physical prediction, like an invisible deck, you might have something. If you put the layout image on a projection screen and talked about how magic used to be done, and how it’s done now. Here’s how this trick would look in 1945, and here’s how it looks now.
-Louie