I was working at Caesars Palace (I can lie, it wasn't magic, but a photo assignment for the Casino) and one morning, in the coffee shop, Grippo was sitting there, alone. I went over to say hello and he came over to my table (a client was with me) and proceeded to do almost an hour of incredible card magic.
Heheheh... Geno will, hopefully, tip, based on the "coat" -- it was his ability to "get" almost with no moves, pauses, nuttin' honey... any named card out of his pocket.
Probably an index, but mainly 40 years of doing it.
This is what most magicians fail to understand. Someone like Grippo will have a KILLER item, a move, a trick, something... and the magician finds out what it is, and practices an hour or so and hasns't a clue.
They don't realize many of the greats have practiced, and or/done an item 10,000 times.
Probably were lousy at it for a couple of years.
My dad had a trick (acrobatic skater) that he practiced every day for a year before he showed it...