Before I get into the nitty gritty on this topic, I’d like you to read this excerpt and visualize the move.
“have it (the card) inserted at the end and prevent the spectator from pushing it quite home by squeezing the deck. Then, with the card protruding about a quarter of an inch. covertly turn the deck: partially over by passing it to the other hand, and get sight of the index.”
Play with it for a while, hopefully you haven’t already seen anyone perform this move and you can establish your own interpretation.
Are you done? Okay, get ready to have your mind blown.
The general consensus is with the card partially protruding, the deck is gripped by the short end farthest from the performer by the right hand and turned end for end, so the deck is face up in the left hand. The index is then glimpsed and the card is pushed flush with the thumb of the right hand.
There’s three reasons I don’t think this is the correct interpretation of Erdnase:
A) Erdnase uses the word covertly. By performing the move this way, you are doing the opposite and openly turning the deck over.
B) Erdnase instructs to turn the deck partially, not completely, over
C) Erdnase says the cards are passed to the other
(right) hand, and in the aforementioned method, the deck stays in the left.
Okay so now we’re back on square one. How do you turn the deck over covertly without being incredibly obvious? I toyed with it for a while and came up with this solution:
The deck is in the left hand, with the same hand positioning of the DPS, with the card protruding about half an inch. In passing the deck to the right hand, the left hand starts turning palm down but stops when the deck is perpendicular to the ground, back of the cards facing right and the long side facing the performer. With the right hand grasp the sides of the deck in the following manner: Right thumb on bottom of the side facing performer, second finger grasping the opposite side (next to the left pinky) and forefinger curled on top, nail against the top card. Here comes the sneaky move:
Bend the cards by applying pressure inwards with both hands. This will allow the performer to “covertly” glimpse a sight of the index of the protruding card. (see image)
You obviously don't want to be in this position long, so as soon as you spot the index the left hand releases its grip and the right hand turns the face of the deck towards the audience. I justify this by explaining that I want to push the card flush as fairly as possible with all angles visible to the spectator to “prove” there is no funny business. I position my right pinky on the short end of the deck closest to the ground and push the card flush with my right forefinger. If you have small hands though, you could just tap the card flush with the left hand. Try it out, it's bold but it works!