pool scores are doubled at the end of the game before calculating its outcome. A third scheme is called Rostov scoring. It differs from Sochi scoring in that the dump penalties for whisters in case the defenders do not win enough tricks are halved. Moreover, dump points are not used. Instead of losing a dump point, a player pays 5 whist points to each opponent, resulting in the same overall result. A common condition for ending the game is that each player must have reached a certain target score in pool points. A player who wins more pool points than that target score performs an operation known as American aid. The surplus pool points are transferred to the player with the greatest number of pool points among those who have not yet reached the target score. The receiving player pays for this with ten times as many whist points, i.e. the equivalent amount. If necessary, this procedure is repeated with another player. If this is not possible because all players have reached the target score (and the game is over), the player reduces his or her dump accordingly to make sure that the pool points can be ignored in the final reckoning. Score sheets and payments Scores are kept on score sheets that have a triangular area designated for each player. Two horizontal lines divide each player's segment of the score sheet into three parts. The top is the dump (sometimes referred to as the mountain), and the last number noted there represents the equivalent (negative) number of dump points. The middle is the pool, and the numbers in this area are used to keep track of the player's pool points. The bottom area is subdivided further. On the left-hand side the player keeps track of the whist points received from the player's left neighbor, and analogously on the right-hand side. If there are four players, the middle corresponds to the player sitting opposite. When a number in an area of the score sheet changes, the new value is written behind the previous value, separated from it by a period. Older numbers are not crossed out, even when they were in error (in which case the correct number is simply entered after the erroneous one). A small circle or diamond in the center of the score sheet, where all the players' triangles meet, is used to keep track of general