All sports around here are age based -- usually defined from Aug 1 to July 31 of whatever year. Still, redshirting is pretty common here, particularly for boys. It appears to be more for social/academic reasons. I have heard that some of the local option/charter schools actively discourage kids with late summer birthdays and guarantee them a spot in the following year K class.
Our school district has an October cutoff for K. All of my kids have winter birthdays and should theoretically be some of the older kids in the class. When my oldest was in K, there were only 2 kids who were younger than her in the class. My other two kids have ended up being in the middle.
Most of the time, redshirting doesn't seem to make much of a difference. Maybe because it is so common here it's the norm. The ones who puzzle me are the kids who have been held back, tested into the gifted program and then the parents complain that their kids could be doing more. Why not start by putting them in the correct grade?!
