I know this is a post from 10 years ago, but for this former semipro magician, this particular trick is “foolproof” and doesn’t require any technical skills, so I can’t see real pros being impressed. Of course, one of the secrets of magic is showmanship and some of the best tricks are really simple. This isn’t criticism of Berglas, more power to him for impressing people.
Having confederates posing as unsuspecting audience members or participating audience members is actually used by even the best of the professionals. I remember watching one top pro and the guy pulled up from the audience was clearly a magician himself. From the way he handled the cards, it was obvious that he was trained.
The interesting point was that the participant was carefully checking each card to make sure it was only one and not two cards together. Someone randomly selected simply would never do that. Actually, because I was first looking at it on my phone, with the poor video quality I thought it may be a rough and smooth deck, where the top of any two card pairs would be the Queen of Hearts, but it was just the confederate carefully counting the cards to ensure the count was correct.
Fooling people is only part of the art. There is also the various technical skills as well as performance and showmanship. Back when I was still an amateur in the 80s, a lot of my fellow magicians would trash talk Copperfield because a lot of his shows weren’t that technical. Well yeah, but he puts on a show that 99.9999% of magicians can never touch.
Even below the pro level, a good semipro or really sharp amateur should be able to understand the tricks of a lot of the professional’s routine. There are only so many ways that things can be done and with experience then it makes it easier to guess.
BUT, that doesn’t mean we could actually become a professional. Generally there is a reason for that divide.
As Penn has said on the show, there are only so many possibilities in magic. In order to allow magicians to fool the dual, they don’t allow Penn and Teller to make too many guesses. If you have watched the first shows, they did allow more guesses, which made it much more difficult for those early contestants.
Pros will also make some moves which are designed to fool other professionals. People appearing on Fool Us routinely do that hoping to throw P&T off.
However, all of this are for the good professionals. Then you get the superstars.
People like Paul Gertner who blow Penn and Teller away. Penn repeatedly tells you that he is the big, dumb guy who is can easily be fooled and Teller is the sharper one. Penn isn’t stupid, of course, but Teller really is among the best.