The other night the National Football League commandeered two hours of prime time on ESPN for what used to be accomplished in a minute or two with a fax machine — the release of next season’s schedule. It was underwhelming television, but in the NFL’s quest to make pro football a year-round attraction it was an important piece of a rather amazing marketing matrix.

Why would even the most dedicated diehards care about a schedule that doesn’t take effect until September? The answer involves a fast-growing style of fantasy football and sports wagering known as “best ball,” for which the betting windows are open 365 days a year, with multi-millions at stake.

Back in January, nearly two weeks before the Chiefs would defeat the 49ers in the Super Bowl to conclude the 2023 season, the leading company in best ball, Underdog Fantasy, began conducting tournaments for the following season. In other words, fantasy football competitors were drafting teams for games that were still nearly nine months away. And it wasn’t for small change: “The Big Board,” featured $2 million in prize money for a $10 entry fee, while “The Little Board” offered $150,000 in prizes for a $3 entry fee.

Matthew Berry, NBC’s top fantasy football analyst, said the ultra early gaming opportunity was certain to appeal to “fantasy football sickos of all shapes and sizes.”

In April, the NFL splashed its annual draft of college players over three days and two networks. The free event in Detroit set an attendance record with over 700,000 people spending an estimated $160 million at downtown businesses. Two days later, Underdog opened its flagship contest, “Best Ball Mania,” with 672,700 entries (up to 150 per person), each costing $25 (a $16.8 million take) with $15 million in prizes, including $1.5 million to first.

In best ball participants draft a team of NFL players, but unlike traditional leagues there are no in-season lineups, trades, or waiver wire pickups — in fact, there’s nothing for the entrant to do following the draft but sit and wait. A computer automatically selects each week’s optimal lineup after the games are played.

But knowing the schedule of games is a vital piece of best ball strategy —taking into account when teams have a bye week and and what the matchups will be in the final do-or-die weeks of the season.

For the NFL, which not too long ago rejected fantasy football and related types of sports gambling, best ball has emerged as a valuable tool in maintaining year-long fan interest. For sportsbooks, including Underdog, Yahoo, DraftKings and other providers, it’s the perfect product because millions of dollars are collected and held for as long as a year before winnings are paid out.

When Best Ball Mania opened, Mr. Berry’s colleague Peter Overzet spoke for the NFL and sportsbooks when he declared, “It’s Best Ball Christmas.”

Peter Funt has produced and hosted TV specials on the Arts & Entertainment and Lifetime cable networks. He also spent five years as an editor and reporter with ABC News in New York. Opinions expressed belong to the writer alone.