There are two ways to look at it. One would be he potential you see combined with genetic realities. But a lot can get in the way until the high school years when you realize the athletic potential, internal motivation and interest by colleges exists.
My kids have college baseball players from my side of the family that go back every generation to 1890. On the other side there are two generations of college baseball players. I played college ball. My ex played college field hockey.
i figured my daughter (the oldest) would develop into a competent high school player. Throu middle school sports were nothing more than fun to her. After losing two consecutive years of undefeated middle school ball 1-0 in the last game of he season my daughter was very quiet. Then she blurted out with fire in her eyes, "Losing really sucks." Softball went from fun to an obsession. She became all everything in high school and played college softball.
My son was the kid everyone thought would get a college scholarship in whatever sport he was playing in the moment from the day he started playing. Through age twelve his favorite sport was the one in season. Whatever sport it was he had to be the best. He's five years younger than his sister. She verballed at fifteen years old. He was ten at the time. As he says with anything she accomplishes, "If she can do it, I can do it better." He was all everything in high school in two sports, recruited for both and plays college baseball.
Neither kid played fall ball until after eighth grade. Starting with high school, even though they were multiple sport stars, baseball/softball became year round between playing and training.
When a kid gets to high school age and you see they are not going to let anything get in the way of baseball success is when you will know. I saw kids star from 9u to 15u who didn't even become high school stars. I saw stars lose interest in baseball due to other sports, girls, jobs, lack of work ethic, alcohol and drugs.