Mahjong is a traditional Chinese game for four people, where players attempt to make combinations of decorated game pieces. Mahjong is a very elaborate game, and mastering it can take much practice. Mahjong requires both experience of the game and mathematical ability to win. A winning strategy requires complex calculations on probability.
Russia is the biggest country in the world, spreading through two continents and 11 time zones. Russia has 4 specific geographical zones that allow gambling, while in the rest of the country these these activities are illegal. Online gambling is illegal in entire Russia, but players playing on foreign sites are not prosecuted.