Boston makes the big move of the offseason so far, turning its rotation into one of the major’s best and widening the gap between its roster and the rest of the American League East. It comes at a huge cost to the farm system, which means -- in turn -- that the White Sox get a big jump-start to their rebuild process.

Chris Sale is a top-10 pitcher in baseball, maybe even top five, and gives Boston a ridiculous rotation for this upcoming season. Sale has finished in the top 10 among AL pitchers in WAR four times, strikeouts five times, strikeout rate five times, ERA five times and FIP five times, all in just five seasons as a starter. He’s produced more value by Wins Above Replacement than any other player from the 2010 draft class, ahead of Bryce Harper and Manny Machado. His slider and changeup are both plus pitches; his fastball velocity has been plus, but was down in 2016, the year of his highest workload to date. He’s under team control for three years, guaranteed at $12 million in 2017 with club options for 2018 and 2019 that, if exercised, give him an additional $26 million. For the next two years, the Red Sox can roll out a rotation of Sale, David Price, Rick Porcello, Stephen Wright, and Eduardo Rodriguez, which produced just about 20 WAR (Fangraphs’ version) last year even with Rodriguez only throwing about half a season’s worth of innings, more than the Cubs got from their five primary starters (17.2) in 2016.