When a match is played without officials, the players are responsible for making decisions, particularly for line calls. There is a subtle difference between player decisions and those of an on-court official. An official impartially resolves a problem involving a call, whereas a player is guided by the unwritten law that any doubt must be resolved in favor of his opponent. A player in attempting to be scrupulously honest online calls frequently will find himself keeping a ball in play that might have been out or that he discovers too late was out. Even so, the game is much better played this way.
Ball touching any part of line is good.
If any part of the ball touches the line, the ball is good. Ball that cannot be called out is good. Any ball that cannot be called out is considered to have been good. A player may not claim a let on the basis that he did not see a ball. Let s play a let.