17 table tennis individual competition, how to make promotion rules?

1 Like the current tournaments, most series are played in groups first. 17 people can be divided into 4 groups (draw lots to group A, group B, group C and group D), and 4 people in each group will compete in a round robin, taking the top two in the group;

2. Play the second stage: A 1C2B1D1A2D1B 2 (8 into 4), and then play the one won in A1C2 and B 1D2, and the other one is the same.