More states now require children to turn 5 before they enroll in kindergarten. And more parents are voluntarily delaying their kids' entry into kindergarten — a step sometimes called "redshirting," after the college athletes who practice in red shirts but do not compete in games as freshmen, giving them an extra year of eligibility. Theoretically, the redshirted child gains by being the oldest rather than the youngest in the class. Not only might he or she be better prepared for classwork, being older might also make the child more confident or likely to be a leader.

Editorial: 'Redshirting' kindergartners getting out of hand