In competitive systems, small early advantages snowball. The “best” get better not only because they’re better, but because they are given more time, coaching, and attention.
A simple example is youth sports: a cutoff date turns age differences into size differences, size into selection, and selection into elite training. By adulthood it looks like pure talent, but the pipeline was tilted from the start.
The same logic appears in school and careers. Once someone is labeled “advanced,” they receive richer problems and higher expectations, which creates real growth. Merit still matters, but opportunity stacks. If you want fair outcomes, you have to notice where the first nudge becomes a lifelong escalator—and where a small redesign could widen the on-ramp.