Apocalypse by Harry Lorayne Volume 16, Number 10 October 1993 Page 2271 et seq.
Personal Comment: I'm not a fan of mixing gambling plots into magic shows. So I can only judge this as a standalone piece, that is disconnected from magic and just seen in the context of a false gambling demonstration. And as such it really is not that bad. And the fact that it is relatively easy makes the whole thing even more approachable.