The term covers an in-game situation which is benefic to only one of the players; it occurs when a player hits the opponent’s two single checkers (blots) at the same time.

It has other names too: Two on the Roof – because the player sends two of the opponent’s checkers on the bar; double bump. A double hit is a good strategic move, because you force your opponent to concentrate on re-entering the two checkers on the board instead of strengthening the position of any other checkers. Also, the opponent must re-enter the two checkers, that being the only legal move at the moment.