The Athletics have spun their wheels recently, finishing in last place in the American League West in each of the last three seasons. That's their longest streak of languishing in the cellar since they did so four straight times from 1940-43.There's cause for optimism in Oakland, however. No franchise improved

The Athletics have spun their wheels recently, finishing in last place in the American League West in each of the last three seasons. That's their longest streak of languishing in the cellar since they did so four straight times from 1940-43.

There's cause for optimism in Oakland, however. No franchise improved its farm system as much in 2017 as the A's, who entered 2017 with a middle-of-the-pack collection of Minor League talent and now rank among baseball's top tier.

The quickest way to beef up a farm system is to trade veterans for prospects, and Oakland did that in a pair of deals with playoff teams in July. The A's shored up the Nationals' bullpen by giving up Sean Doolittle and Ryan Madson in exchange for Blake Treinen and a pair of premium 2016 Draft picks, left-hander Jesus Luzardo (third round) and third baseman//shortstop Sheldon Neuse (second). Luzardo was a potential first-rounder before having Tommy John surgery as a high school senior but has flashed three plus pitches since returning, while Neuse displayed his offensive potential by batting .321/.382/.502 with 16 homers and reaching Double-A during his first full professional season.

Two weeks after that move, Oakland picked up three past or present Top 100 Prospects from the Yankees in exchange for Sonny Gray . Dustin Fowler is a potential 20-20 center fielder, shortstop/outfielder Jorge Mateo is one of the fastest players in the Minors and had 52 steals and 60 extra-base hits last year, and right-hander James Kaprielian can flash four plus pitches and control to match. Fowler is recovering from a ruptured patellar tendon in his right knee and Kaprielian must bounce back from Tommy John surgery, but their upside remains enticing.

The A's also added significant talent via the Draft. Outfielder Austin Beck (first round) was one of the best all-around athletes available, shortstop Kevin Merrell (supplemental first round) had the best speed among top college prospects, outfielder Greg Deichmann (second) had some of the best power potential and shortstop Nick Allen (third) was the best defender in the entire Draft. Outfielder Lazaro Armenteros and catcher Sean Murphy, who had signed in 2016, boosted their stock by taking positive steps forward in their development.

• A's Top 30 Prospects

While they didn't raise their already high profiles, Franklin Barreto reinforced the notion that he's one of the game's best hitting middle-infield prospects and A.J. Puk solidified his status as one of its top left-handed pitching prospects. All in all, Oakland's system hasn't been this strong since the end of last decade. That crop included Andrew Bailey , Trevor Cahill , Josh Donaldson, Giovany Gonzalez and Doolittle -- all of whom became All-Stars before getting traded -- and helped fuel the A's last three playoff teams in 2012-14.

Here are four more farm systems that improved the most in the last year:

Phillies

Philadelphia had the best system of anyone on this list at the start of 2017, and now it has one of the best systems in baseball. Having right-hander Sixto Sanchez emerge as one of the game's top pitching prospects, second baseman Scott Kingery break out with 26 homers and 29 steals and shortstop J.P. Crawford reclaim his mojo in the second half certainly helped. So did drafting polished center fielder Adam Haseley with the No. 8 overall pick, swapping big leaguers for prospect depth (most notably getting righty Enyel de los Santos from the Padres for Freddy Galvis ) and adding a solid corps of international signees headlined by shortstop Luis Garcia .

Angels

After Michael Trout graduated to the big leagues in early 2012, Los Angeles was in the discussion for baseball's worst farm system every year since. Two huge moves a week apart in December ended that talk, as the Angels signed Japanese two-way star Shohei Ohtani and shortstop Kevin Maitan, the top prospect on the 2016 international amateur market who became a free agent in the wake of the Braves scandal. They also drafted tooled-up outfielder Jo Adell and polished right-hander Griffin Canning with their first two picks in June, then signed Bahamian speedster Trent Deveaux the next month.

Tigers

Detroit went from contending for the better part of the previous 11 seasons to losing 98 games in 2017, and the club embraced rebuilding along the way. The Tigers turned J.D. Martinez, Alex Avila, Justin Wilson , Justin Upton and Justin Verlander into Jeimer Candelario and seven members of MLBPipeline.com's Tigers Top 30, including right-hander Franklin Perez, outfielder Daz Cameron, catcher Jake Rogers and infielder Isaac Paredes. They also stole righty Alex Faedo with the 18th overall choice in June and added two more seven-figure bonus babies in catcher Sam McMillan (fifth round) and shortstop Alvaro Gonzalez (Venezuela).

Marlins

Miami should have gotten more when it traded Giancarlo Stanton and Marcell Ozuna , and its system still ranks in the bottom third. Yet the Marlins acquired 10 of their 15 best prospects in the last 12 months: right-handers Sandy Alcantara , Jorge Guzman, Nick Neidert , Merandy Gonzalez and Zac Gallen plus outfielders Magneuris Sierra and Brayan Hernandez and shortstop Christopher Torres via deals, plus left-hander Trevor Rogers and outfielder Brian Miller with their top two Draft picks.