LOS ANGELES: The schmaltz is piled on thick, and if the comedy were any broader it would require an Imax screen, but still there’s something touching about how hard Billy Crystal and Bette Midler hustle to peddle the threadbare material that makes “Parental Guidance” a tolerable, if uninspired, movie-going experience.

As “the other grandparents” who are given a rare opportunity to bond with their grandchildren, Billy and Bette seem well aware they have to entertain the paying audience as much as the juvenile characters.

Artie Decker (Crystal) has just lost his longtime gig as “De Voice of the Fresno Grizzlies” when the minor-league baseball team decide to upgrade the outfit with the sort of talent that knows its way around a Facebook page or a Twitter account.

Despondent Artie’s not excited at the news that he and his wife Diane (Midler) have been recruited to babysit the three kids of their daughter Alice (Marisa Tomei).

There are predictable gags built around technologically challenged Artie. Fortunately, Crystal’s arsenal of rim-shot-ready rejoinders hit the mark more than they miss. While his character has been given more of an emotional arc than Midler’s, it’s still nice to see Midler strutting her stuff in her first onscreen comedy role in years.

Tomei is always a welcome presence, even when she’s saddled with what’s essentially a one-note character for most of the film.

Director Andy Fickman and screenwriters Lisa Addario and Joe Syracuse could have mined some fresher stuff from this frequently played ballgame.