I ran into so many roadblocks when I started seriously looking into going into academia when I was 16-17; if you don't have top science fairs or olympiads your chances of getting into top academic undergrads are already at risk, which has negative compounding effects down the line compared to the positive compounding effects of those that do get these, especially if you are a white or asian male. Close relatives of academics and people going to top magnet schools in major metro areas have huge headstarts compared to everyone else. Having a good IQ is just one of many requisites into going into academia, accomplishment-oriented credentials are much more valuable in your early career than things like regular standardized test scores
Many friends from grad school have tenure-track jobs. None of them, as far as I know, participated in these contests. I would bet that things effectively reset once you start grad school and again once you’re in a faculty job.
It is true that academic recognition tends to snowball. Winning your nth grant or fellowship is exponentially easier than the first one “because you have a track record.”
i dont think the math adds up.
As far as whites, alumni preference is typically as strong or stronger a weighting than affirmative action in undergrad admissions, and segregation wasn't outlawed until around 50 years ago meaning there are less alumni for non-whites to draw on, and many of the schools received federal money during segregation.