#6 Trading for Robbie Ross (0.8 WAR)
After a failed transition to starting, the Texas Rangers traded Ross to Boston for Anthony Ranaudo. Ranaudo was hit pretty hard at triple A Round Rock and was batted around in 2 starts. While his strikeout rate improved in the minors, he's still walking more batters than you'd like and being hit hard. Ross was mediocre in the early going for the Sox as a lefty specialist but when he was used for full innings later in the year, he excelled. All told he looked like the above average reliever he was in 2012 and 2013. He's cheap in arbitration next season, as well. For now it looks like the Sox made out here.
#5 Trading for Alejandro De Aza (1.3 WAR, 60 games)
Acquired by the Sox from the orioles for minor league swingman Joe Gunkel, the Red Sox got surprisingly good production out of De Aza. After being an above average outfielder offensively and passable defensively, he was traded in August to the Giants for minor league pitcher Luis Ysla. This second trade was one of the first moves made by new president of baseball operations Dave Dombrowski. It was to make room on the roster for more playing time for Rusney Castillo and Jackie Bradley. While Ysla is a wild card, the Aox got great value out of a streaky player in De Aza and flipped him for similar value as they traded for him.
#4 Signing Rich Hill as a free agent in August (1.6 WAR, 4 starts)
After appearing in a handful of games as a strict left handed batter specialist for the Yankees in 2014, Rich Hill bounced around a bit in 2015 and eventually found himself in the independent leagues. After 2 strong starts, incoming new president of baseball operations Dave Dombrowski decided to bring in Hill to make a few starts at the end of the season. After years of arm trouble and mostly being deployed as a short reliever in recent years, Hill made 4 very good starts, two of them excellent. It will be interesting to see if he gets another chance in the Sox rotation or somewhere else in 2016 as a 36-year old.
#3 Acquiring Wade Miley (2.5 WAR, 32 starts)
The trade of Allen Webster and Rubby de la Rosa for Wade Miley was meant as trading potential for consistency. Webster blew up in Arizona and it seems the Diamondbacks will be lucky to get a middle reliever out of him. De La Rosa has potential but surrendered an absurd amount of home runs both at home and on the road. There's still back end starter potential though.
The trade looked pretty bad for the Sox, too, as Miley had a horrendous first half. However, it seemed he was getting extremely unlucky on balls in play. In the second half of the season he was exactly the pitcher the sox traded for. While former general manager Ben Cherington may have jumped the gun in giving him a preseason extension, it's looking ok now. Miley is a solid rotation anchor. Even if de LA Rosa pans out as a decent starter and Webster finds himself, it's still a good trade for the Sox.
#2 Recalling Jackie Bradley Jr from Triple A Pawtucket (2.2 WAR in 74 games)
While not a trade or free agent signing, recalling a player from the minors is indeed a transaction, so Jackie Bradley’s return to the majors counts. His offensive struggles continued in his first stint in the Majors in 2015, and he struggled again when he returned the second time. But all of a sudden, Bradley exploded offensively. With his usual above average defense, Bradley put up production worthy of a league-average regular in only half of a season. That’s also with some struggles at the end of the season. It’s hard to say how much of that offensive outburst was for real, but at least the Sox know that he won’t be a negative on offense anymore.
#1 Recalling Eduardo Rodriguez from Triple-A Pawtucket (2.5 WAR in 21 starts)
While Blake Swihart, Henry Owens, and Rusney Castillo all got their feet wet in the majors this season and made positive contributions, no one made the impact upon arriving from the minor leagues that Eduardo Rodriguez did. While Andrew Miller was excellent for the Orioles after being traded for him, it’s likely that Miller would have ended up with the Yankees in the offseason anyway. Therefore, this trade looks like one of the best that Ben Cherington ever made. Rodriguez got off to a hot start, had a few real stinkers, but rebounded to have an above-average season overall. He’s going to be cheap for the next couple of years and it will be interesting to see if they decide to give him a contract extension to lock in arbitration seasons.