Question: How are the groups divided?
Answer: The first 4 positions of the regular season are placed as heads of each group (A1, B1, C1 & D1), this is row #1. The next 4 make-up the second row and are randomly selected to be in one of the groups (A2, B2, C2 & D2). From the regular season's standings, teams in 9th, 10th, 11th & 12th positions are randomly put in row #3 (A3, B3, C3 & D3) and so on the fourth row is done in the same way. That leaves the last 2 teams in 17th & 18th. Since the last team in a standing usually play against team with the highest ranking, they are placed randomly in groups A & B (A5 & B5).