HOLLYWOOD — At the far end of the practice field on a Saturday morning, a line of nine-year-olds in shoulder pads that nearly swallowed them waited their turn on a bathroom scale, because in youth tackle football a child’s eligibility begins with a number.

The program runs each fall for players from about 7 to 12, grouped into divisions by age and weight so that the biggest child in a bracket cannot line up across from the smallest. Games fall on Saturdays. Practice takes three weeknights under whatever light the park can spare. Everyone who coaches or works the snack table does it for free.

“We are down from where we were ten years ago, and I would be lying if I said I didn’t know why,” said Victor Aguilar, 38, who coaches the middle division and played in the same league as a boy. “Parents read the same headlines I do. My job is to teach a kid to tackle with his head out of it, and to prove to his mother that I mean it.”

Enrollment in youth tackle football has slid for a decade as families weigh the risk of head injuries, and many have shifted children into flag leagues that keep the sport without the collisions. Aguilar’s program added a flag division of its own, partly on principle and partly to keep families in the tent until they are ready to decide.

Denise Trujillo, 44, sits on the volunteer board and spends more of the season raising money than watching football. Helmets must be reconditioned and certified every year, the insurance is not cheap, and no child is turned away over the fee, which means the shortfall lands on car washes and a raffle.

“People think the hard part is the games,” Trujillo said. “The hard part is a stack of helmets that each cost more than a season of youth soccer, and a budget that rides on how many plates of carne asada we sell in October.”

Not every parent is sold. Reuben Castellano stood at the fence watching his younger son play flag while his older son, once a tackle player here, has moved to cross country.

“One of mine loves the contact and one of mine I pulled, and I don’t apologize for either call,” Castellano said. “What I like is that they let me choose without making me feel like I quit on anybody.”

For the families who stay, the draw is partly the game and partly the ladder it leans against. Coaches point up the road to Hollywood High, where a few Saturday players eventually surface on Friday nights, and where the smallest kids on the scale this morning already picture themselves.

The middle-division game kicked off a little late on a field still wet with dew, in front of parents who cheered every play and winced at a couple. When it was over, the losing side lined up for handshakes, and a coach reminded them, twice, that practice was Monday.