When I was younger (10?), I played on an AAU basketball team. Everyone on my team was white, except for me and a half-black kid. Our very first game, we played an all black team. They pressed us relentlessly and the end result was not pretty.
Blacks mature faster than whites, who mature faster than Asians, so at this level of basketball, black kids have a physical maturity advantage. The playing field is much more level in high school, because the maturity advantage of blacks has mostly disappeared. Of course, blacks, on average, still hold an advantage in overall athletic ability, but it is not insurmountable by any means. In high school, our all white+me team did manage to beat some very black teams by playing a disciplined brand of basketball.
Most people who have been exposed to competitive basketball understand that “black” does not always equal “good at basketball”. A good percentage of adults who like to play pick-up basketball who did not grow up in a basketball environment are extremely gullible and believe “black”=”good at basketball”, so they pick black people first, even if the black person in question sucks. Asians are especially prone to this kind of discriminatory behavior as most Asians spent more time at Kumon math class than at gyms in their youth. FOBs are even more prone to this behavior as their exposure to black people prior to arriving in the states is pretty much limited to watching the NBA which is dominated by black people who can jump really high.
Several of the post players on my AAU team never ended up being much good in high school, even though they were pretty good at a younger age. The reason? While they were considered “tall” when they were young, they ended up peaking in height at less than 6-3, which is not tall enough to play down low in competitive high school basketball, especially if you are white and can’t really jump all that high. They were relatively slow, weren’t much good at handling or shooting the ball, but had great post moves, which unfortunately doesn’t really help when the defender is several inches taller.
The lesson here is that if you are training your kids to play basketball, teach them guard skills, no matter how tall they may seem to be. It is easier to learn post skills than guard skills at a later age. This has become a trend–many professional forwards and centers these days were trained as guards when they were younger. You no longer see too many traditional post players–coaches want forwards who can shoot and handle the ball a bit.