When the Red Sox hired David Dombrowski as president of baseball operations in August 2015, they had a big league club headed toward its second consecutive last-place finish, yet hope in the form of the best farm system in baseball. Fast forward to today, and they're the two-time defending American League East champions but the system is thinner than it has been in more than a decade.
• Red Sox's Top 30 Prospects list
The changes in fortune in the Majors and Minors are related. Dombrowski hasn't been afraid to trade elite prospects to acquire the likes of Craig Kimbrel, Thomas Pomeranz and Chris Sale. The system also has contributed potential stars Andrew Benintendi and Rafael Devers, both of whom arrived in Boston ahead of schedule.
:: Team Top 30 Prospects lists ::
The Red Sox should be able to contend for at least another year or two without getting much immediate help from the system, whose only potential impact prospect on the cusp of the big leagues is third baseman Michael Chavis. The early returns on a 2017 Draft that began with right-hander Tanner Houck (first round) and outfielder Cole Brannen (second) are promising. The loss of Venezuelan catcher Daniel Flores, who died of cancer in November four months after signing for $3.1 million, was a tragedy for the organization while also resulting in a major setback for the farm system.
Biggest jump/fall
Here are the players whose ranks changed the most from the 2017 preseason list to the 2018 preseason list.
Jump: Bryan Mata, RHP (2017: NR | 2018: 4)
Fall: Christopher Johnson, LHP (2017: 12 | 2018: NR)
Best tools
Players are graded on a 20-80 scouting scale for future tools -- 20-30 is well below average, 40 is below average, 50 is average, 60 is above average and 70-80 is well above average.
Hit: 55 -- Sam Travis (Pedro Castellanos)
Power: 60 -- Michael Chavis
Run: 70 -- Cole Brannen
Arm: 60 -- Bobby Dalbec (C.J. Chatham, Michael Chavis, Danny Diaz)
Defense: 60 -- Cole Brannen
Fastball: 65 --Tanner Houck (Ty Buttrey, Darwinzon Hernandez, Joan Martinez)
Curveball: 65 -- Jay Groome
Slider: 60 -- Mike Shawaryn
Changeup: 60 -- Bobby Poyner
Control: 60 -- Bobby Poyner

How they were built
Draft: 21
International: 9
Breakdown by ETA
2018: 9
2019: 5
2020: 10
2021: 4
2022: 2
Breakdown by position
C: 0
1B: 3
2B: 1
3B: 3
SS: 4
OF: 2
RHP: 11
LHP: 6