The Yankees entered 2016 with a promising farm system, headlined by Jorge Mateo, Aaron Judge and Gary Sánchez and featuring some enviable depth behind them. That system couldn't quite crack MLBPipeline.com's Top 10 list, but it still offered hope to a franchise that hadn't won a playoff game in three straight seasons for the first time since the early 1990s.
Mateo's stock took a hit during an up-and-down season that included a suspension for insubordination, Judge arrived at Yankee Stadium -- but did so with serious swing-and-miss concerns -- and Sanchez graduated to the big leagues by slamming 20 homers in 53 games. Despite all that, New York now has the best and deepest farm system in the game -- and also the most improved over the past 12 months.
How exactly did they pull this off? The Yanks' most obvious prospect upgrades came at the Trade Deadline in July, when they helped set up a classic World Series by sending Aroldis Chapman to the Cubs and Andrew Miller to the Indians. Both of those clubs gave up four players to land an elite reliever, and those hauls included a shortstop who since has established himself as one of baseball's five best prospects (Gleyber Torres from Chicago) and three recent first-round picks (outfielder Clint Frazier and left-hander Justus Sheffield from Cleveland, plus outfielder Billy McKinney from the Cubs).

Those may have been New York's splashiest moves, but far from the only ones that added talent to the system. The Yankees got the No. 4 overall pick in the 2015 Draft, enigmatic but intriguing right-hander Dillon Tate, from the Rangers in another July trade, for Carlos Beltrán. In November, they parted with another veteran (Brian McCann) to get a pair of live-armed righties (Albert Abreu, Jorge Guzman) from the Astros.
Amid concerns about his age (19 at the time of the Draft) and signability, New York stole outfielder Blake Rutherford with the 18th overall choice in June, and he might be a more athletic version of David Justice. And while they already were in the system at the start of the year, players such as third baseman Miguel Andújar, right-hander Chance Adams and lefty Jordan Montgomery appreciably raised their profiles.
The Yanks haven't had this much talent in the Minors since Derek Jeter, Andy Pettitte, Jorge Posada, Mariano Rivera and Bernie Williams were developing in the early 1990s. Here are four other systems that noticeably improved during the course of this year:
White Sox
In just two days at the Winter Meetings, Chicago elevated its system from the bottom 10 to the top 10 and perhaps even the top five. (We'll officially rank the systems again when we revamp the organization Top 30 Prospects lists in February.)

On Dec. 6, the White Sox shipped Chris Sale to the Red Sox for the best prospect in baseball (infielder Yoán Moncada), one of the best pitching prospects in the game (right-hander Michael Kopech), a potential five-tool center fielder (Luis Alexander Basabe) and a reliever who can hit 100 mph (Victor Diaz). On Dec. 7, they used Adam Eaton to get two more top pitching prospects (righties Lucas Giolito, Reynaldo López) and a 2016 first-rounder (righty Dane Dunning) from the Nationals.
A banner Draft that included catcher Zack Collins, righties Zack Burdi and Alec Hansen, and outfielders Jameson Fisher and Alex Call also gave the system a huge boost. Add in July trade acquisition Charlie Tilson, and 12 of Chicago's best 15 or so prospects weren't White Sox property at the start of the year.
Padres
After doing everything he could to strengthen the big league club in an unsuccessful attempt to contend in his first year on the job, San Diego GM A.J. Preller has reversed course and tried to build for the future ever since. You could construct a very respectable Top 30 Prospects list using only players acquired during 2016.
The Padres had three first-round picks that they turned into right-hander Cal Quantrill, infielder Hudson Potts and lefty Eric Lauer, and they also drafted high-upside players such as outfielder Buddy Reed and righties Reggie Lawson and Mason Thompson. They easily led baseball by spending $34.6 million on international amateur bonuses (and another $31.2 million in overage tax), grabbing coveted players such as lefty Adrian Morejon ($11 million), outfielders Jorge Ona ($7 million) and Jeisson Rosario ($1.85 million), and shortstops Luis Almanzar ($4.05 million) and Gabriel Arias ($1.9 million).
On the trade front, San Diego got infielder Fernando Tatis Jr. from the White Sox in a deal for James Shields, nabbed right-hander Chris Paddack from the Marlins for Fernando Rodney, acquired elite pitching prospect Anderson Espinoza from the Red Sox in a swap for Drew Pomeranz and added slugger Josh Naylor as part of an Andrew Cashner deal with Miami. (Those last two trades were tinged with injury-related controversy, but allowed to stand.) And in what may have been an unprecedented move, the Padres wound up with the first three players selected in December's Rule 5 Draft: right-hander Miguel Diaz, catcher Luis Torrens and shortstop Allen Córdoba.

Brewers
Milwaukee made this list a year ago thanks to some astute drafting and trading, and was back at it again in 2016. The Brewers dealt for valued prospects before (infielder Isan Diaz, catcher Jacob Nottingham), during (outfielder Lewis Brinson, right-handers Luis Ortiz and Phil Bickford) and after (infielder Mauricio Dubon) the season.

Milwaukee also got a pair of potential impact bats with its top two selections in the Draft, outfielder Corey Ray and third baseman Lucas Erceg. While a number of their better holdover prospects had rough years, the Brewers did get a breakout from right-hander Brandon Woodruff, who led the Minors with 173 strikeouts.
Reds
Cincinnati also appeared on this list a year ago, based on the returns for trading Johnny Cueto, Mike Leake, Todd Frazier and Chapman. The only viable prospect the Reds dealt for in 2016 was left-hander Max Wotell, part of the package from the Mets for Jay Bruce, but they did strong work in the Draft and on the international market.
The Reds' Draft began with the top college bat (third baseman Nick Senzel), one of the most exciting high school athletes (outfielder Taylor Trammell) and the best all-around college catcher (Chris Okey). Cincinnati followed by stocking up on live arms such as right-hander Nick Hanson and lefty Scott Moss, and also signed speedy T.J. Friedl for a nondrafted free agent-record $735,000. Two big-ticket Cubans, shortstop Alfred Rodriguez ($7 million) and righty Vladimir Gutierrez ($4.75 million), highlighted the Reds' international crop.