“It’s never going to go away,” Noah Garden, M.L.B. executive vice president for business and sales, said of ticket sales . “It isn’t going to die. But it’s going to change. There are going to be a different number of people that want to purchase tickets a different way.”

There already are. Four teams introduced the ballpark pass in 2015, and now 18 of the 30 M.L.B. teams have some type of subscription option, which varies in price from $30 each month for standing room only to $125 for a guaranteed seat. While it has not been enough to reverse the downward trend in ticket sales, baseball executives believe it is attractive to younger fans, who are used to paying for subscription services like Netflix and Spotify.

“You’re not going to get rich off the ballpark pass,” said Brooks Boyer, the White Sox’ senior vice president for sales and marketing. “But you’re getting people in the park.”

That is important in part because the energy from full stadiums comes across on telecasts, and because with an aging fan base, baseball is trying to cultivate the next generation of fans. But it is also a delicate dance. If teams lower ticket prices too much, they could devalue their product and drive away those customers who still pay hundreds or thousands of dollars each season for a premium experience.

The Miami Marlins, who attract the smallest average crowd in baseball, are trying to woo fans with a host of new ticketing options. They include a “ticket bank” in which fans buy credits at a discount before the season that they can use to purchase tickets during it. But with dozens of ticket types, the Marlins risk angering fans who later notice they could have purchased their tickets for cheaper.

The hope is fans don’t “second-guess themselves on their next purchase as to whether this is the right place, right location, right time,” said Adam Jones, the Marlins’ chief revenue officer.

The most popular new ticketing trend, though, is the ballpark pass (and its variants). According to M.L.B., fans in their mid- to late-20s represent the largest group of ballpark pass buyers.