Shuffling when the deck is favorable to the players; not shuffling when the deck is unfavorable to the players.
Shuffling when it is clear that the remaining cards favor the players.
Either shuffling when the deck is favourable to the players or not shuffling when the deck is not favourable to the players.
shuffling by the dealer in Blackjack, when the deck tends to favor the players, while s/he avoids shuffling a deck that favors the house.
shuffling by the dealer in Blackjack, when the deck tends to favor the players, while avoiding a shuffle when the deck favors the house.
Shuffling when the deck is favorable to the players, while avoiding a shuffle when the deck is unfavorable to the players.