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I have come across a reference in one of my own notebooks to a principal or possibly an entire effect called Splitting The Difference. It appear to have similarities to an OOTW principal. My reference mentions it was detailed in an old edition of Genii. Problem is, I can't for the life of me remember what I was writing about and how I came by this information. Anyway, it seems quite interesting and may help me with a problem I am currently having with an effect
Anyone know anything about this effect? Whether it is an OOTW like principal? Whether it is purely a card trick and where I can find some more information about it?