SAN DIEGO -- The first domino fell in November.

Closers are luxuries, and when a team has other needs to fill, they're almost always trade bait. The San Diego Padres had organizational needs to fill, so they dealt Craig Kimbrel to the Red Sox and received four prospects in return.

On the surface, it was a run-of-the-mill offseason deal, one club looking to contend immediately and one looking to build for its future. For the Padres, it signified more. The Kimbrel trade marked a philosophical turning point.

In the preceding year, a number of trades and free-agent signings had left San Diego's farm system depleted. Burdensome contracts presented serious obstacles toward replenishing that depth.

"There was opportunity in the short term to try to take a chance to put a competitive team on the field," said Padres general manager A.J. Preller of his team's spending spree during the 2014-15 offseason. "But there was also understanding at the time that we were going to acquire assets that potentially could be valuable to other teams. ... As a baseball group, you're always talking about: 'Here's the best possible scenario, but also here's other scenarios.'"

The best-case scenario did not play out. San Diego finished 74-88 in 2015 and had already parted with many of its top youngsters.

"That's your lifeblood," Preller said of the farm system. "You need to fill your organization with talented guys."

It was Preller's job to replenish the Padres' so-called "lifeblood," and in 2016, he has taken a three-pronged approach to doing so. In a nine-month span, San Diego entirely restocked its farm system. The Padres have acquired eight of their top nine prospects since the 2015 season ended, and 20 of their top 30.

Gone are Trea Turner , Joe Ross , Zach Eflin and Matt Wisler . In are Anderson Espinoza , Manuel Margot , Josh Naylor and Cal Quantrill. Here's how the Padres got there:

The Draft

Top 30 Prospects: No. 5 Cal Quantrill, RHP, Stanford; No. 9 Eric Lauer, LHP, Kent State; No. 14 Buddy Reed, CF, Florida; No. 26 Reggie Lawson, RHP, Victor Valley HS (Victorville, Calif.); No. 28 Mason Thompson, RHP, Round Rock (Texas) HS

After sacrificing their first-round pick in 2015 to sign James Shields , the Padres were on the opposite side of the equation in '16. Ian Kennedy and Justin Upton declined qualifying offers, giving San Diego a pair of additional first-round selections.

Throw in a lottery round B pick, and the Padres owned six Draft choices among the first 85 -- the most in the Majors.

All spring, Preller insisted, "the Draft is not a crapshoot." It became a catchphrase of sorts for him during Draft week.

With a steady dose of early selections, the Padres found themselves in on players at every tier, putting additional burden on the amateur scouting department. In a normal year, a handful of players simply aren't options because of Draft position.

San Diego didn't have the luxury of leaving stones unturned in 2016. The team drafted Stanford's Quantrill at No. 8 overall, a certifiable risk, given that he hadn't thrown an inning since coming off Tommy John surgery. High-school righty Thompson was also returning from the same operation. Lawson dealt with an oblique injury during his senior year of high school.

The Padres' Draft strategy, it seemed, was to use their plethora of picks to create a margin for error that allowed them to take risks on players they might not have otherwise selected.

"It's not risk," scouting director Mark Conner said at the time. "We're getting guys with upside and feel like once we implement them into our system of player development, it's going to come to fruition.

"It's a probability play for us that other people see as a risk because they didn't do the same work."

International signings

Top 30 Prospects: No. 6 Adrian Morejon, LHP, Cuba; No. 13 Jorge Ona, OF, Cuba; No. 21 Luis Almanzar, SS, Dominican Republic; No. 22 Gabriel Arias, SS, Venezuela; No. 29 Jeisson Rosario, OF, Dominican Republic

Like the rest of the baseball world, the Padres loved Yoan Moncada. Easy to see why. Moncada -- MLBPipeline.com's No. 2 overall prospect -- came to San Diego's backyard in July and took home MVP honors at the SiriusXM All-Star Futures Game, launching a mammoth home run off the second deck in left field.

A year prior, the Padres had considered doling out serious money for Moncada. But Preller's tenure was just beginning. Continuity was lacking on the scouting staff, and San Diego hadn't yet invested elsewhere during that signing period.

If Moncada agreed with the Padres, they would've been hit with the maximum penalty, forced to sit out the following two signing periods with only Moncada to show for it.

"Do we try to invest in Yoan Moncada?" Preller asked. "Or do we try to invest in a large group?"

Seventeen months ago, Moncada cost the Red Sox $63 million, including taxes. That's approximately what the Padres have spent while running riot on the international market this year. They've inked eight of the Top 30 International Prospects, and about 30 overall -- with more likely to sign.

Of course, this is a group of players who are mostly half a decade away from making a big league impact. But Preller stressed the importance of bringing them along together.

"We want to have a program where we have our own guys come up through our system and learn the Padre way of playing baseball, from the time they're 18, 19, 20 years old," Preller said. "That's a good plan; probably as good a way to build a championship club as possible."

Trades

Top 30 Prospects: No. 1 Espinoza, RHP (Pomeranz trade); No. 2 Margot, CF (Kimbrel trade); No. 4 Naylor, 1B (Cashner trade); No. 7 Javier Guerra, SS (Kimbrel trade); No. 8 Chris Paddack (Rodney trade); No. 16 Enyel de los Santos, RHP (Benoit trade); No. 17 Logan Allen , LHP (Kimbrel trade); No. 19 Hansel Rodriguez, RHP (Upton trade); No. 20 Carlos Asuaje , IF (Kimbrel trade)

Moving Kimbrel was only the beginning. In the two months leading up to Monday's non-waiver Trade Deadline, the Padres flipped Shields, Fernando Rodney , Drew Pomeranz , Melvin Upton Jr. and Andrew Cashner .

In return, they received a total of eight players -- all of whom were younger than the five that departed. Four of those players slotted right into San Diego's top 20 prospects.

Of course, the Kimbrel deal alone handed the Padres four of their current top 20 -- and two players, Margot and Carlos Asuaje -- who could begin to impact the big league club before the 2016 season ends.

"You're constantly trying to build, you're constantly trying to add," Preller said. "There are all different ways to do it. We've seen it on the pro scouting side, starting with the Kimbrel trade, then the deals that we've had leading up to the Deadline -- [Pomeranz], Rodney, etcetera."

The Pomeranz and Rodney trades stand out in the bunch, mainly for the fact that neither were with the organization a year ago. Preller bought low on the pair, and he sold high.

Rodney cost San Diego less than $1 million over three months. He netted Paddack, the system's No. 8 prospect (who appears ticketed for elbow surgery).

Pomeranz essentially cost the Padres Yonder Alonso . He netted them Espinoza, now the club's top prospect. (Alonso's OPS has not yet eclipsed .700 this season. Espinoza is the No. 20 prospect in baseball at age 18 and has drawn comparisons to Pedro Martinez.)

The vision

Preller is always eager to pore over his nightly game reports from Minor League managers and staff. Given the recent influx of organizational talent, he's downright giddy when they come in now.

"When you get these guys all on the field together -- that's what we've been building toward," Preller said.

There's inherent risk in putting the fortunes of a franchise on the shoulders of college-age kids. But San Diego is playing a numbers game: bring in enough young talent and a percentage of it will pan out.

It's not that simple, of course. Prospects don't grow into Major Leaguers on their own. The biggest challenge remaining is for the Padres to develop their revamped farm system into big league victories. If they don't, the past nine months will have been for naught.

For now, however, the Padres feel as though they've stacked the deck in their favor, infusing their farm system with an all-out assault on the Draft and the international and trade markets.

"We had talked about trying to line that all up together," Preller said. "You line up the timing of those guys coming up together, playing instructionally together, playing their first season together. Even if it's different age groups, it's guys that are going through their first experience in professional baseball together.

"Hopefully, you have that come up together in the next couple years at Petco. We looked at [the last year] as an opportunity to line that all up."

AJ Cassavell covers the Padres for MLB.com. Follow him on Twitter @ajcassavell.