Aren't those prodigies who get identified and given special education that is not available to most? They may not be all the useful for judging the quality of math education in general in the US.
Yes, but the ability to identify prodigies and give them the resources to realize their full potential is part of an education system, too. I don't know the full details of the IMO participants, but the team is geographically diverse.
Of course, another aspect of the education system are the resources given to the average student, and I don't think there is much debate that the US could do better here.
