While baseball teams fine tune their rosters for opening day, Major League Baseball Advanced Media (MLBAM) has some changes of its own, including tweaks to free and subscription content. Sports Business Journal, which has added a gate to its walled garden and is providing some free links, has the details.

Some highlights:
-- Video enhancements: The streaming rate is being upped again to nearly hi-def quality, to 1.2 Mbps from 700 kbps and a 16X9 wide-screen format. Working with Microsoft (NSDQ: MSFT), MLB.com is adding tag-based video search based on lots of metadata, including type of play, people in the clip, teams, dates, etc. Also, mobile video alerts are coming.

-- Redesign: MLB.com and the 30 team sites get a more video-centric feel.

-- Game tracking: The Gameday app, produced with SportVision, is adding type of pitch (If you’re serious enough to follow Gameday, it matters) and, for a subscription fee, in-game video highlights.

Numbers: MLB.TV had 400,000-plus subscribers in 2007; MLBAM projects the usual 20 percent growth in 2008, according to SBJ.  FastCompany also takes a look at MLBAM: “In a typical day during the season, as many as 11 million people visit the site. Three million watch video. The average user watches for an unheard-of 37 minutes per viewing—only one minute less than the average time spent watching baseball on TV. The league, in a way, is becoming its own broadcast partner, even sending announcing crews to games not covered by ESPN (NYSE: DIS) or local stations. It’s not hard to imagine how that could jeopardize lucrative TV contracts one day ... “

Searching for MLB Network CEO: Meanwhile, not content with its online and mobile video presence, MLB is searching for a CEO for its upcoming cable network. From the prospectus obtained by SBJ: The CEO is expected to “create significant asset value to MLB’s owners; deliver new opportunities for baseball’s fans and sponsors to build an even stronger relationship with the game; and provide strategic value to MLB in its negotiations with media partners for years to come.”