Marseillais chess Marseillais chess Marseillais chess (also called Double-Move chess) is a chess variant in which each player moves twice per turn. The rules of the game were first published in Marseillais local newspaper "Le Soleil" in 1925. The variant became quite popular in the late 1930s with such chess grandmasters as Alexander Alekhine, Richard Réti, Eugene Znosko-Borovsky, and André Chéron playing it. A player can either move one piece twice or move two different pieces on his turn. Castling is considered a single move. When a player gives check on the first move, he loses the second move of his turn.
Null-move heuristic program must make the full-depth search. This approach makes two assumptions. First, it assumes that the disadvantage of forfeiting one's turn is greater than the disadvantage of performing a shallower search. Provided the shallower search is not too much shallower (in practical implementation, the null-move search is usually 2 or 3 plies shallower than the full search would have been), this is usually true. Second, it assumes that the null-move search will produce a cutoff frequently enough to justify the time spent performing null-move searches instead of full searches. In practice, this is also usually true. There are a class