[Old Redhound]

First of all it should be up to the Parents and the kid.

If sports is what your about. Go for It. They will get the same benefits that the others get.

Greater Maturity (Physically and Mentally).
Better chance of playing and enjoying sports (Isn't high school more fun that way). There are great life lessons to learn playing sports (winning and losing).
Parents get to have their kids home one extra year.

If your kid is making straight A's now, most likely, if the parent is involved, they will make straight A's the holdback year.

If they are smart, use the extra year to complete AP courses (Lets say just 4 courses) and pass the tests. At Corbin you can take 4 classes at EKU (assuming you have a 21 ACT before your jounior year). At 3 hours per that is 24 college credit hours virtually free. Call the college of your choice and see what that is worth.

I recommend to all hold your kid back (preferably start them late in Kindergarden). All of my kids are in school as old as legally possible by KHSAA rules.