The New York Yankees were sellers at last season's trade deadline, a first since the 1980s. They moved established big leaguers Aroldis Chapman, Andrew Miller, Carlos Beltran and Ivan Nova in four separate trades for 12 total prospects. They Yankees decided to take a step back and build for the future.

At this year's trade deadline, the Yankees decided the future is now. They made it official at Monday's non-waiver trade deadline with a four-player swap that brings Sonny Gray to New York and sends prospects Jorge Mateo, James Kaprielian and Dustin Fowler to the Athletics.

None of the three prospects going to Oakland were acquired in last year's trades. Kaprielian and Fowler were both original Yankees draft picks, and Mateo signed with the club as an international free agent. Gleyber Torres and Clint Frazier, the two headliners in last summer's trades, were said to be off-limits.

The Yankees have reversed course and gone from sellers to buyers in one year's time because the youth movement has worked beautifully. Homegrown All-Stars Aaron Judge, Gary Sanchez and Luis Severino are the backbone of a roster that comes into Monday sitting atop the AL East at 56-47. They've gone 8-2 in their past 10 games and the division is oh so winnable.

For all the talk about a youth movement, the Yankees will always be a win-now team, and Monday's trade combined with the trade that brought Todd Frazier, David Robertson and Tommy Kahnle from the White Sox a few weeks ago improved the club's chances dramatically. There's also the recent Jaime Garcia trade with the Twins. They made those three trades while giving up only one piece off their big-league roster, and that was Tyler Clippard, who was sent to the White Sox to offset salary.

The Yankees were never going to build exclusively from within. No team does that. What the Yankees have done instead is develop a core from within and supplement it from the outside. We're used to those supplementary players being big money free agents. Instead, the Yankees have dipped into their farm system to deal extra prospects. Consider the prospects they've dealt:

The Yankees acquired four substantial upgrades to their MLB roster (Gray, Frazier, Robertson, Kahnle) without trading their top prospects. They dealt from positions of depth (the outfield, most notably) and traded some damaged goods, as Fowler and Kaprielian are currently rehabbing major injuries. The Yankees kept their best prospects and moved the others for MLB help. That's what every team aims to do.

Over the past calendar year, the Yankees have built an exciting young core and supplemented it using the depth of their farm system. Judge, Sanchez, Severino and Frazier (Clint, not Todd) are thriving in the big leagues, and others like Torres, Chance Adams and Justus Sheffield are ready to arrive in 2018. Now they've added impact pieces like Gray, Robertson and Kahnle. This is a three-part process.

  1. Acquire as much talent as possible.
  2. Incorporate that young talent into the MLB roster.
  3. Trade the leftovers for more MLB roster help.

The Yankees did that in a year. Other teams are doing it in three or four years. Yes, their money helps -- the Yankees were able to trade Miller and Beltran because they signed those guys as free agents in the first place -- so the rebuild shouldn't have taken that long. It's still striking that the rebuild happened this quickly.

A year ago the Yankees were an old team with no real youth on their MLB roster. Now they're loaded with quality young players at the big-league level with more in the farm system, and they're already adding supplemental pieces from outside the organization. The Yankees are a really good team right now. The way they're set up, they could be a great team in 2018 and beyond.