18 teams example

Round 1) Team 1 vs Team 2
Round 2) Team 1 vs Team 3
Round 3) Team 1 vs Team 4
Round 4) Team 1 vs Team 5
Round 5) Team 1 vs Team 6
Round 6) Team 1 vs Team 7
Round 7) Team 1 vs Team 8
Round 8) Team 1 vs Team 9
Round 9) Team 1 vs Team 10
Round 10) Team 1 vs Team 11
Round 11) Team 1 vs Team 12
Round 12) Team 1 vs Team 13
Round 13) Team 1 vs Team 14
Round 14) Team 1 vs Team 15
Round 15) Team 1 vs Team 16
Round 16) Team 1 vs Team 17
Round 17) Team 1 vs Team 18