Why do regions get different allocations towards to Challenger Series The allocation is based on the size of membership per region in addition to the membership performance. Related articles What is the Challengers Series field size? How will the second half of 2021 unfold and how will the Regional QS Rankings work? How do CS surfers qualify for the CT? New Championship Tour Format for 2021 and Beyond How many events will count towards 2021 Challenger Series qualification? Comments 0 comments Article is closed for comments.