When the Red Sox finished in last place in the American League East in 2015, they had a strong farm system and a rising homegrown core that paid off with division titles in each of the next three years and a World Series championship in '18. After sinking to the cellar with a 24-36 record this season, their turnaround doesn't figure to be as immediate.

Boston just posted its worst winning percentage since 1965 and its system isn't poised to plug many of its holes. Corner infielder Bobby Dalbec and right-hander Tanner Houck impressed in late-season trials, stating their cases to play significant roles in 2021. But the rest of the Red Sox's best prospects haven't played above Double-A and are a year or two away from Fenway Park.

The system placed just 25th in MLB Pipeline's in-system talent rankings, though Boston added depth with a series of trades this year. Dealing Mookie Betts to the Dodgers may not have been necessary or wise, but it did give the Red Sox their top-rated prospect (middle infielder Jeter Downs) and best catching prospect (Connor Wong). In-season trades of Heath Hembree, Mitch Moreland, Kevin Pillar and Brandon Workman netted four more Top 30 Prospects in outfielder Jeisson Rosario, third baseman/second baseman Hudson Potts and right-handers Connor Seabold and Jacob Wallace.

Boston has helped its cause by finding players later in the Draft or for bargain prices on the international market. Dalbec (fourth round, 2016), right-handers Noah Song (fourth, 2019) and Thad Ward (fifth, 2018) and outfielder Jarren Duran (seventh, 2018) all lasted at least 118 picks in the Draft. Righty Bryan Mata and outfielder Gilberto Jimenez signed for a combined $35,000.

FARM SYSTEM RANKINGS

2020 Midseason: 25 | Preseason: 25
2019 Midseason: NR | Preseason: NR
2018 Midseason: NR | Preseason: NR
2017 Midseason: NR | Preseason: NR
2016 Midseason: 7 | Preseason: 6
2015 Midseason: 2 | Preseason: 1

Only the top 10 systems were ranked from 2015 to 2019 preseason; the top 15 systems were ranked 2019 midseason.

TOP PROSPECTS
1. Jeter Downs, SS/2B (No. 40 on Top 100)
2. Triston Casas, 1B (No. 71)
3. Bobby Dalbec, 3B/1B (No. 100)
4. Bryan Mata, RHP
5. Gilberto Jimenez, OF
Complete Top 30 list »

NOTABLE ADDITIONS

Draft: Nick Yorke, 2B, 1st round (No. 11); Blaze Jordan, 3B, 3rd round (No. 15); Jeremy Wu-Yelland, LHP, 4th round; Shane Drohan, LHP, 5th round. Complete Draft list »

Trade: Jeisson Rosario, OF (No. 16); Hudson Potts, 3B/2B (No. 20); Connor Seabold, RHP (No. 23); Jacob Wallace, RHP (No. 24).

Waivers: Deivi Grullon, C.

Though Yorke was the biggest surprise in 2020's first round, the Red Sox believe he can become an elite hitter, and they used the bonus savings he gave them to land the slugging Jordan in the third round. Rosario has the highest ceiling among Boston's midseason trade acquisitions -- he offers potential solid hitting ability, speed and center-field defense -- while Seabold's pitchability could land him in the 2021 rotation.

2021 IMPACT PROSPECT

Bobby Dalbec, 3B/1B (No. 3): Few players can match his raw power, which translated into eight homers in 80 big league at-bats this summer.

2022 TOP PROSPECT

Triston Casas, 1B (No. 2): He not only is one of the best power prospects in the Minors, but he's also the best hitter in the system and a defensive asset at first base.

BEST TOOLS

Hit: Triston Casas
Power: Bobby Dalbec
Run: Jarren Duran
Arm: Brainer Bonaci
Field: Gilberto Jimenez
Best athlete: Jarren Duran

Fastball: Bryan Mata
Curveball: Jay Groome
Slider: Tanner Houck
Changeup: Connor Seabold
Control: Denyi Reyes

HOW THE TOP 30 WAS BUILT

Draft: 16
International: 7
Trade: 7

Twelve of the Red Sox's best 15 prospects came via the Draft, including first-rounders Casas (2018), Groome ('16), Houck ('17) and Yorke ('20).

TOP 30 BY POSITION

C: 1
1B: 1
2B: 1
3B: 5
SS: 6
OF: 5
LHP: 2
RHP: 9

Boston's talent is distributed fairly evenly among the positions, with its collection of slugging corner infielders (Casas, Dalbec, Jordan) perhaps standing out the most.