We have 90 players, format as followed
Round 1
90 players start, 60 players advance
Round 2
60 start, 42 advance
Round 3
42 start, 30 advance
Round 4
30 start, 18 advance
Round 5
18 start, 12 advance
Round 6
12 start, 6 advance to finals
Round 7
Finals
Can you explain a ...