In reply to JLS:
The World Ranking is used to determine which group you are in and is also used to determine the starting order.
The WR is different from the World Cup ranking in that it is based on the results for the last year and includes the World Championships (if there was one last year). The World Cup ranking gets reset to zero at the start of each season.
In group 1 you get the competitors with the ranking 1, 4, 5, 8, 9, 12, 13 etc
In group 2 you get the competitors with the ranking 2, 3, 6, 7, 10, 11, 14 etc