I'm not saying that's the only reason. I think the majority of boys who are born late summer should be held back a year, both of my nephews spent an extra year in preschool. I don't know of anyone who regrets holding them back, but know if many who regretted sending them, and having them be the youngest.First to the OP: Cut off date is September 31 here. School starts in mid-August.
I'm going to go off on a tangent here. My son's birthday is in late September and we decided to start him late. There were a lot of reasons for it -- academic and social -- but NONE of them were sports related. It really bothers me that people say "they did it because of sports." And I knew it was coming as soon as I saw the subject of the post... someone ALWAYS says it.
It really trivializes the decision and makes it sound like parents are willing to sacrifice their kids' education for the possibility of some high-school "fame" on the sports field... rather than the real reason which was to make their education better. There may be some weirdos that look at their 4 year old and see the next star quarterback, but do you really think that's why "a lot of boys" are started late?
My son's in high school now and he does play sports. He's an average player for his grade level. He's not a star. Of the other families I know who also started their kids late (boys and girls) there's not a star athlete among the bunch... and I don't think anybody's parents expected them to be. And several don't play sports at all.
I was replying to the person who mentioned sports. I do know parents who held back primarily for sports, and know of several who had their boys repeat 8th grade in private schools solely for sports (basketball and baseball).