On the contrary Mr. Kaufman--here I positively know what I am talking about; for it is not necessary to have read your book in order to assess an effect which I have seen performed by Berglas himself (albeit on video) several times, and to form the opinion that I no doubt share with others who are acquainted with the basic moves of card manipulators (palming, double-lifting and the like)--that any time that the magician holds the pack, it is far from impossible for him to locate a chosen card, remove it from its current position, and do just about anything he wishes with it. Only the fool that you take me for (or wish I was) would be at a loss to understand it after a moment's sobriety. You say they have "no idea how their card appears on top, or on bottom, or at their chosen number, in the deck". If that is the case, then they really need to read my blog--the poor things.
Simply put: the only inexplicable method is the one that is indeed done without the performer touching the cards (or having someone else handle them for him, precisely as he wishes).
I am perfectly willing to concede that the version of The Berglas Effect described in your book does not require stooges. Not having read your book, it were illogical to accuse me of ever having promulgated the notion that that variation is anything other than what appears in black and white. But--can it be considerd the definitive Berglas Effect, merely because David Berglas' name is on it?
It is certainly not The Berglas Effect that those that are fascinated by the premise (which is largely based on the well known criteria) are eager to learn. It is apparently The Law Of Averages, Hit And Miss, and Best Of Luck all rolled into one. Discovering that the performer is allowed any number of opportunities to persuade the volunteer to cut the cards, and that one's chances of successfully setting up the deck for the climax are dubious, has got to be less than overwhelming.
Are you suggesting that the 'one-on one' version is essentially the same as the one involving multiple participants, in which the performer handles the cards little or not at all? If that were the case, my question would be: Why would a skilled card worker restrict himself to moves designed for any untutored Tom, Dick or Harry, when he could achieve the effect much more efficiently using the tricks of his trade? Clearly, the means that David Berglas employes when holding the cards himself are different than those he would instruct an uninitiated spectator to perform! Conversely--it is absurd to suggest that David would resort to mathematics and mind games when all he needed was his well regarded sleight of hand.
As for who picks the participants--it would only be a truly fair choice if the audience were to determine the issue democratically. We all know it is a typical ploy to allow any number of folks to shout out numbers, or raise hands--merely to delegate the decision to an individual, be it the performer or any member of the crowd. If that is "the whole point", I'm sorry to say it's quite a feeble one.