National standard mahjong: it is a kind of playing method of mahjong. Its rules were formulated by the General Administration of Sport of the People's Republic of China in July 1998, and then applied in many international and domestic mahjong competitions, so it is called national standard mahjong.
Single fishing will: The general card type of mahjong is four pairs, one pair, and this pair is called "will". If four pairs have been made up and there is only one pair, the method of playing cards is called "single fishing".
Key points of national standard mahjong rules:
1. Four rounds in one round, four sets in each round, no Lianzhuang, 16 sets in each round.
2. There is no limit on the number of cards to be played. Even if my fellow scouts play the cards you just played, they can still play.
3. Seat rotation.
4. In the case of concealed bars, the four cards are facing down and need not be shown to others. Only after the game is over, whether there is a draw or not, it needs to be opened for the opponent to see.