This trade isn't particularly flashy, but it gets a job done. We get an affordable, young, consistent 4th starter.
Why the Red Sox do it: Britton, at this point, is a lottery ticket. Maybe he figures it out with the mental game and control, but he probably doesn't. He also is taking up a valuable 40-man roster spot, although he will be pitching in high-A. The Sox need a starter so that they can put Bard or Aceves back into their natural roles in the pen. With Beavan, you know what you are going to get. He pitches to contact, but he does it reasonably well. He gets righties out well and induces a lot of ground balls. He is under team control for another 5 years and is only 22 years old. Ramos is a nice piece but will easily get buried behind the outfeild depth we have in our system at this point. Perkins is a bit of a throw in because the Celts traded their Kendrick Perkins away, but in all seriousness, he is one of many, many, high-ceiling outfielders in our system who will have a tough time making the bigs because of that monstrocity of a contract we have manning left field.
Why Seattle does it: Although Beavan is young and affordable, he is pretty much maxed-out, and he could be like Nick Blackburn and get figured out at the major league level. Meanwhile, as a team that is sure to be one of the 5 worst teams in the league, they should try to maximize the value of every piece they have. In Britton, they get a guy who made a few top-100 lists last year and can still throw 97 miles per hour, meanwhile, they get Henry Ramos and Kendrick Perkins who could be very talented big-leaguers one day.