High school football


High school football is gridiron football played by high school teams in the United States and Canada. It ranks among the most popular interscholastic sports in both countries, but its popularity is declining. According to the Washington Post, between 2009 and 2019, participation in high school football has declined by 9%.

Rules

The National Federation of State High School Associations establishes the rules of high school football in the United States.
Since the 2019 high school season, Texas is the only state that does not base its football rules on the NFHS rule set, instead using NCAA rules with certain exceptions shown below. Through the 2018 season, Massachusetts also based its rules on those of the NCAA, but it adopted NFHS rules in 2019.
With their common ancestry, the NFHS rules of high school football are largely similar to the college game, though with some important differences:
At least one unique high school rule has been adopted by college football. In 1996, the overtime rules originally utilized by Kansas high school teams were adopted by the NCAA, although the NCAA has made three major modifications. Firstly, through the 2018 season, each possession started from the 25-yard line. Since 2019, this remains in force through the first four overtime procedures. Secondly, starting with the third overtime, teams must attempt a two-point conversion following a touchdown. Finally, Since 2019, the fifth and all subsequent overtimes are two-point conversion attempts instead of possessions from the 25-yard line, and successful attempts are scored as conversions instead of touchdowns.
Thirty-four states have a mercy rule that comes into play during one-sided games after a prescribed scoring margin is surpassed at halftime or any point thereafter. The type of mercy rule varies from state to state, with many using a "continuous clock" after the scoring margin is reached, while other states end the game once the margin is reached or passed. For example, Texas uses a 45-point mercy rule only in six-man football; for 11-man football there is no automatic stoppage but the coaches may mutually agree to use a continuous clock.
Most Canadian schools use Canadian football rules adapted for the high school game. The exception is British Columbia, which uses NFHS rules as used in the United States.

Safety and brain health concerns

Robert Cantu, a Professor of Neurology and Neurosurgery and Co-Founder of the CTE Center at the Boston University School of Medicine, believes that children under 14 should not play tackle football. Their brains are not fully developed, and myelin is at greater risk in shear when the brain is young. Myelination is completed at about 15 years of age. Children also have larger heads relative to their body size and weaker necks.
Chronic traumatic encephalopathy is caused by repeated brain trauma, such as concussions and blows to the head that do not produce concussions. It has been found in football players who had played for only a few years, including some who only played at the high school level.
An NFL-funded study reported that high school football players suffered 11.2 concussions per 10,000 games or practices, nearly twice as many as college football players.