On MLB.com, Gammons will be a featured writer on the site's upcoming columnist initiative, which will showcase the nation's premier baseball writers.
"We think the written word is very important," said Bob Bowman, MLBAM president and Chief Executive Officer, on a conference call. "As the largest employer of baseball writers, adding somebody who understands the game and writes about it so eloquently is very exciting for us.
"He gives us a world-class analyst on baseball."
On MLB Network, Gammons will be immediately featured on the nightly studio show "Hot Stove," and going forward will offer analysis and commentary on breaking news and special events like the Trade Deadline, First-Year Player Draft, Winter Meetings and Postseason.
"It's hard to imagine a reporter who is more deeply associated with a sport than Peter is with Major League Baseball," said Tony Petitti, President and Chief Executive Officer of MLB Network. "Having Peter associated with MLB Network is an incredible opportunity and another great step for MLB Network as we head into our second year.
"This is an important step for us. Part of Peter's responsibility will be to generate content for us and come up with programming ideas. We'll be developing programs for Peter. This will be a great outlet for all of his expertise."
Echoing those sentiments on Tuesday, MLB.com executive vice president and editor-in-chief Dinn Mann expressed delight over the hiring of "one of the best-known baseball observers."
"His illustrious 40-year career has included coverage of some of the most important moments in baseball history," Mann said. "We are thrilled he will be the anchor of our soon-to-be-launched daily columnist Web site that will include this country's best baseball writers."
As part of his MLB Network visibility, Gammons will also contribute to the "30 Clubs in 30 Days" program and do studio work on short, documentary-style pieces and other select programming. Gammons will also be a regular analyst on MLB Tonight, MLB Network's signature nightly studio show.
On Tuesday, Gammons announced his decision to depart ESPN after two decades at the sports network. And concurrent with the MLB announcements, NESN also announced a multiyear agreement with Gammons to serve as studio analyst and reporter beginning in January.
"It's just a great opportunity to stay in the game, a great situation for where I am in my life and in my career," Gammons said on Tuesday night.
"This had nothing to do with ESPN, but with where I am in my life and getting to do the things I love to do," said Gammons, whose affiliations with MLB Network and MLB.com will begin as soon as the Winter Meetings end.
Gammons has devoted his professional life to baseball, and is most heartened by the opportunity to become affiliated with a network and Web site devoted to the same passion.
"After 40 years covering baseball, this is a great and daunting opportunity," he said. "My journalistic life has revolved around baseball, and to be involved with people whose network is devoted to baseball -- and baseball only -- is something I look forward to with excitement. I see so many directions we could go, the opportunities are boundless.
"This lets me move on to another stage of my career, with tremendous respect for the people with whom I'll be working."
"We all wish pitchers and catchers reported tomorrow. One of the greatest things about baseball is that it is held to a higher standard than any other sport, which holds those of us who care about it to a higher standard. I hope I can contribute to that standard.
"For generations, baseball has been the writers' sport, from John Updike to Roger Angell to Tom Boswell. To be afforded the opportunity by MLB.com to write about breaking news, inside information, issues, players, people, history and the perspective of the game's place in society from Jackie Robinson to our current generation of socially-conscious players like Torii Hunter, Carlos Pena, and CC Sabathia is a forum that makes this next chapter of my journalistic life exciting and rewarding."
That journalistic book already teems with accomplished chapters.
He is the winner of the 2005 J.G. Taylor Spink Award for outstanding baseball writing, presented to him during the Hall of Fame's induction ceremony.
Gammons also is a three-time (1989-90, 1993) winner of National Sportswriter of the Year by the National Sportscasters and Sportswriters Association.
He had been ESPN's baseball analyst since 1988, as well as a writer for ESPN The Magazine and ESPN.com.
Gammons had begun his career as a reporter for the Boston Globe in 1969 and wrote a weekly Sunday baseball column for many years. He has also worked for Sports Illustrated covering the National Hockey League, college basketball and Major League Baseball (1976-78, 1986-90). He has also served as a contributor to Baseball America. In 1984, Gammons wrote the critically acclaimed book Beyond the Sixth Game, a look at free agency.