Wonging
From the BJ21.com Glossary:
Wong, Wonging, Wonger. To back count the cards dealt at a particular table and to then join play only when the count indicates the game has swung to the player's advantage, and then to leave when the count indicates the game has turned unfavorable. The term has been expanded to include playing in any favorable situation in a number of different games. It is named after blackjack author and BJ21.com proprietor Stanford Wong, who popularized this method of play.