The instructor drew lots to decide the order of appearance. In each round, the instructor freely chooses the trainees and the challenged teams, and the trainees choose their own opponents. At the same time, similar to the blind selection of the "wheat seal right", each tutor has a special right that can only be used once-"seal right", which can determine that any student of the challenger can not play in a single round, thus making his students in a relatively favorable position in a single round.