I have always been curious about the number of high school athletes that go on to play in college and the pros, but have always heard a wide range of statistics, so I decided to take a shot at consolidating the numbers across sports and gender. For most of the numbers, I found a great resource, scholarshipstats.com, which tracks the number of high school players in the US along with the number that advance to play on a Division I, II, or III NCAA team. To get the data for the final piece of the funnel, the total number of players in the pros, I looked up how many players are drafted per year to each top tier professional league in the United States.
The visualization below includes major sports in which both males and females have a chance to advance from high school to the top tier league within the US in their respective genders. For this reason, the visualization does not include football. If you are looking for how many high school football players go on to play in college and get drafted to the NFL, there are 1,121,744 boys playing high school football. Of those, 87,256 play in college (1 in 13), and 254 are drafted to the NFL (1 in 4,416 who play in high school; 1 in 344 who play in college).