I don.t think it is really an issue of can a player play a year or two up, if the player is talented enough, and knows what the situation is he/she can decide to play or not. The issue is really fairness and integrity. If a player assumes parity in age amongst all competitors, and some are older than others by a year, that calls into question the integrity of both the tournament and players parents of the offending players. it is unfair, or cheating to play your child in an age group that you know they don't belong, and cowardly to excuse that behavior by saying the child was left behind for any reason.