For the "Rookie of the Year" and "Player of the Year" nominations, awards should only be given for first-place finishes.
Regarding the "Best Player" award for a specific faction, tournament organizer, etc., it's possible to create perpetual awards (I completely agree with Kosta N). Because this encourages activity and competition.
As for the term "rookie," here's a suggestion: a rookie is someone who has not won more than 12 games in one season against fewer than 4 players. That is, there should be a total of 12 wins, and not all against the same player, but at least once against 3 players and 9 times against one player.