Bill James, the famed statistician who's been an adviser and consultant for the Boston Red Sox since 2002, announced Thursday that he's leaving the organization.

"I leave the Red Sox on the best possible terms," the 70-year-old James wrote on his website. "I am still friendly with everyone that I have worked with there, from the owners to the security guards. I still intend to ... watch every Red Sox game. Well, maybe not EVERY game; retirement means I don't have to stay up to watch them play a four-hour game in Seattle ending at 1:30. In exchange for that, next time we win the World Series, I won't get a ring."

James was a pioneer of baseball analytics, gaining fame with his annual "Baseball Abstract" from 1977 through 1987, and then "The Bill James Handbook," which projects statistics for every major league player each year.

He joined the Red Sox as their senior baseball operations adviser in November 2002. Two years later, they won their first World Series since 1918. The Red Sox went on to win three more titles with James on staff.

A consultant in recent years, the club described his position as working "with senior management and the baseball operations department to provide research and analysis of special projects, and on-going concerns."

In his statement, James said he's just retiring from the Red Sox and not baseball projects overall.

"I have two books written that I need to get published; I have more books that I am writing and more books that I want to write," James wrote on his website. "The annual Handbook will be out in a week or so. I have a TV project in the works; I have big dreams. I'm going to get a dog, and a bicycle, and my wife and I will travel, as we always have. "... To the Red Sox: it's been a blast. Thank you all."