It’s been a big week for the New York Yankees. First the team won a bidding war for Japanese pitching phenom Masahiro Tanaka. YES NetworkThen, today, Fox announced that it will raise its stake in the team’s YES regional sports network to 80% from 49%. When the deal closes, expected by the end of March, YES Network will be consolidated into Fox’s financials. The companies didn’t disclose the size of Fox’ investment; it paid $3.4B for its minority stake in 2012. But it “underscores our commitment to growing our global sports portfolio with offerings that are exceptional and unique,” says Fox Deputy COO James Murdoch. The entity that owns the baseball team — the Steinbrenner family’s Yankee Global Enterprises — will own the remaining 20% of the network. The group’s chairman, Hal Steinbrenner, says that it’s “eager to continue working with 21st Century Fox as we explore ways to take YES to even greater heights.” It has a lot of ground to make up: YES’ ratings plummeted more than 31% in last year’s baseball season as the Yankees, beset by injuries, fielded comparatively few stars and failed to make the playoffs. But Fox is making a long-term bet on sports. Last year it converted motor sports network Speed into a general sports channel Fox Sports 1, and turned Fuel TV into Fox Sports 2. COO Chase Carey calls sports “the most powerful programming out there” although he recognizes that the high costs for licensing rights make it “a double-edged sword.” Fox’s effort will be helped with the addition of YES, which typically is the nation’s most-watched regional sports network. Tracy Dolgin, YES’ current CEO, will keep his job after the change in control.