Edge ball usually refers to the trajectory of the ball in football or other sports games. Although it is still a certain distance away from the goal, it has already grazed the net or goalpost and entered the opponent's goal. Therefore, the player who is scored can get a point. In the field of novels," edge ball " usually referred to some love plots. Although the relationship between two people seemed to brush by, it actually contained opportunities and possibilities. This kind of plot often appeared in novels to make readers feel the wonder and uncertainty of love.