Shifting the cut is the sleight of hand solution around the protection of cutting the deck. Honest players developed the tendency towards cutting the deck as a way to foil second dealing, bottom dealing, and peeking. However, advanced sleight of hand permits the cheat to overcome the cut.
The traditional cut involves the dealer pushing the deck towards another player, who cuts the deck into two smaller piles. The dealer then picks up the pile that was on the bottom and places it on the top of the other pile. Therefore, cards that were at the top or on the bottom of the deck are now lost in the middle of the deck. Shifting the cut involves the cheat returning the deck to its original order, while being watched by the other players.
In effect, the cheat manages to place what was the top of the deck BACK ON TOP of the deck. This can be done as follows:
1) With one hand, the cheat simply picks up the 'top pile' and quickly places it on top of the other pile. Such an elementary way would most likely require distraction with the cheat's free hand. If nobody is looking, the cheat may manage to pull it off without anybody even noticing or suspecting.
2) As a more complex move, the cheat passes the 'bottom pile' over the top of the other pile, but quickly drops the 'bottom pile' right beside the other pile, picking up the other pile just as quickly. The cheat then drops this other pile, the 'top pile' back onto the other cards, not disturbing the order of the cards. This would obviously require tremendous speed, and most likely, some distraction.
3) Also requiring great dexterity, the cheat indeed picks up the 'bottom pile' and places it on top of the other pile; effectively, an honest cut. The cheat, however, does not drop the 'bottom pile' on the other pile squarely; the 'bottom pile' sticks out ever so slightly from the other pile (called "the step" by stage magicians). The cheat then picks up the deck as it is, and while pretending to square the deck, actually uses the step to replace the 'bottom pile' at the bottom of the deck. Done quickly enough, the order of cards is not disturbed.
All of these maneuvers require great skill, but help the cheat overcome the cut. Shifing the cut is worthless on its own, however, and is combined with another form of cheating that takes advantage of having beat the cut.