Last year the Atlanta Braves traded Shelby Miller to the Arizona Diamondbacks for Dansby Swanson, Aaron Blair, and Ender Inciarte. The trade was widely panned that the Diamondbacks overpaid for Miller. Miller was considered a very good pitcher, perhaps at peak a #2 starter, but nothing near an elite pitcher. Miller had just come off an All-Star season for the Braves in 2016 and had 4 years of team control left. If Miller could improve, he'd be an incredible asset under budgeted team control for quite some time.
The haul the Braves got for Miller was Blair, the MLB.com pre-2016 #56 prospect in baseball, Swanson the pre-2016 #8 overall prospect, and a MLB starter Ender Inciarte. Inciarte was a relatively light hitting outfielder, but with elite defense. He posted an incredible 5.3 WAR in 2015 with a 2.6 defensive WAR.
The 2016 results was about as horrific for the Diamondbacks as one could have ever imagined. Miller struggled with his mechanics and was even demoted to the minor leagues at one point. He finished the year 3-12, with a 6.15 ERA, and -0.7 WAR.
On the other hand Swanson continued to impress in the minors and got a small callup, Blair made it to the majors in 2016 (although struggled), and Inciarte produced a solid 3.8 WAR and ended up winning a Gold Glove.
Some rumors point to the Diamondbacks looking to move Miller, as a change of scenery might be the best thing for him. In other words, the trade is just looking absolutely horrific for them.
Just a few weeks ago, the Boston Red Sox pulled off a blockbuster deal, trading for the White Sox's Chris Sale. Sale is a five time All-Star and has placed in the top 6 of Cy Young voting 5 years in a row. His past five years he's posted WARs of 5.9, 6.9, 6.6, 3.3, 4.9. He's a completely different beast compared to Miller. In addition, Chris Sale is under control for three more years at a very team friendly salary.
So while Chris Sale is a far superior pitcher, has 3 years of team control at a good (although more costly than Miller) price, one probably would have thought the Red Sox would have had to give up a much bigger haul for Sale.
But as I thought about it, I felt like the Red Sox got Chris Sale for about
the same price the Diamondbacks paid for Shelby Miller. Lets take a look.
For Sale, the White Sox got Yoan Moncada the MLB.com pre-2016 #3 prospect in baseball and pre-2017 #1 prospect in baseball, Michael Kopech the pre-2016 #98 prospect and pre-2017 #30 prospect, Luis Alexander Basabe, and Victor Diaz. The latter two prospects aren't on any top 100 rankings but were considered top 20 prospects in the Red Sox organization.
While the pre-2017 #1 prospect in baseball is better than the pre-2016 #8 prospect in baseball, and the pre-2017 #30 prospect is better than the pre-2016 #56 prospect, it's not that different. Both of the top two prospects traded were high value middle infield prospects and RHP prospects.
The difference of course is the two other minor leaguers vs Ender Inciarte. Inciarte was an established major league starter with 5 years of control. By most people's estimation, that's better than the two lower end prospects the White Sox received. One can make an argument that the Braves haul was better than the White Sox one solely based on the fact that Inciarte was already a solid major league starter.
So the Diamondbacks appeared to pay an elite #1 starter price for Shelby Miller. Making the trade look even worse than it already did.