I've found this effect to be a real fooler. I've performed it a few times already, and it has been
quite successful. I agree with some of the posts I've seen elsewhere, that it's really for an
informal setting, like a gathering of friends, or even a house party.
A lot has been
written about Rick Lax and the mathematical methods he uses in some of his releases. While there is
certainly a mathematical element to this, it's not the focus, nor does it take anything away from
the effect.
This effect reminds me a lot of Bob Hummer's Fantastrik - but that used way
more mental calculations - and did not have the added benefit of the participant naming the number.
This trick is easy to perform, is baffling, and I believe entertaining. Rick's touches with
the invisible card bit is the kind of detail that really elevates this trick to more than simply a
math-based card trick.
John