Yes, I understand the concept. Like Breanna Stewart,

Sonia Citron did better at tournament time. Up until the tournament games, she scored 11.8 ppg, 43.3 fg%, 15.37 Efficiency rating, and 48.3 efg%—all excellent! During the tournament games she scored 12.8 ppg, 56.1 fg%, 16.25 Efficiency rating, and 58.5 efg%. (When I say tournament games, I mean ACC and NCAA.)

I agree with you that because of the longer season and that the games are against tougher opponents, you would think that the "Freshman Wall" would be real. For those two, at least, it was not. As I say, we need more data.

Maybe you are on to something with all the summer playing time in high school. The fact that some freshmen do even better against late season, tournament-quality opponents, probably says more to the character of the player.