The Avant Dernier is a very popular streaking system. This betting system is very simple. A player bets only on the result of the sequence of the last 2 games. For example, the wins are player, banker, player, banker, banker in this case a system recommends betting on the banker.
In reality this system is very doubtful. There is not any relation between one hand and the following, and those who bet relying on this system do this on the naive assumption that a winning streak for either side is likely to go on.