I would expect that PG/EG participants in math competitions find themselves up against other PG/EG participants in short order, at which point the number hours of study and practice become a significant determining factor in success. Once "Who wants it more?" is a major part of the activity, it becomes very easy for someone to say, "Not me," or, "Eh... I want it, but not that badly."
This is not right. If you are talking about top 0.1%, then that's +3SD to +6SD (or a bit higher) which is a huge range. There's only so much ground that can be made up with effort.
