Trying to establish a bigger baseball beachhead on Saturday nights, Fox said it would broadcast MLB games in primetime for eight consecutive weeks, the network’s most ever.

The games will be regionalized, beginning May 19 with five possibilities including Boston against Philadelphia and Chicago’s White Sox vs. its Cubs. Every team in the U.S. will appear at least twice during the run.

“We’re pleased that we were able work with our partners at Major League Baseball to develop our most extensive primetime schedule yet,” said Fox Sports co-prexy and COO Eric Shanks. “Our hope is to increase viewership and by featuring so many teams, create additional exposure for the game’s many stars so they become more familiar to a broader fan base.”

Fox began experimenting with regular-season Saturday night broadcasts in 2010, most notably in a game between the New York Yankees and the Los Angeles Dodgers that June. A year ago, three baseball Saturday nights in May averaged approximately 4.2 million total viewers.

While ESPN has long offered weekly primetime games — “Sunday Night Baseball,” for example, has been in place for more than two decades — this will be the biggest primetime effort by a broadcast network for MLB regular-season games in one season since the shortlived “Baseball Network” that ABC and NBC combined to attempt in 1994-95, an effort that was short-circuited in part by the 1994 players’ strike.

Before that, you’d have to go back to the 1980s — prior to ESPN’s first major deal with MLB in 1989 — to find regular primetime MLB game coverage on a broadcast network.

Fox’s new schedule could impact local cablers and broadcasters, who aren’t allowed to broadcast MLB games during Fox’s Saturday window. Traditionally, teams have moved non-Fox games away from the afternoon window into the night, but presumably would have to reverse course during this eight-week stretch.