Legal analysis: infringing cylinder: refers to the cylinder drawn with the player's torso as the round bottom. Probably refers to the player's airspace area. For example, if a player is standing with a ball, the defender puts his hand firmly on the attacker's head in advance to stop the attacker from shooting. The attacker lifts the ball and shoots, but the defender doesn't move and keeps his hand on the opponent's head.

Legal basis: Sports Law of the People's Republic of China.

Article 1 This Law is formulated in accordance with the Constitution for the purpose of developing sports undertakings, enhancing people's physique, raising the level of sports and promoting the construction of socialist material and spiritual civilization.

Article 2 The State shall develop sports undertakings, carry out mass sports activities and improve the physical fitness of the whole nation. Sports work is based on national fitness activities, and the combination of popularization and improvement is implemented to promote the coordinated development of various sports.