SAN DIEGO -- The Padres, quite suddenly, are one of the most exciting teams in baseball. Top prospects Fernando Tatis Jr. and Chris Paddack have played no small part. Left-handers Eric Lauer and Joey Lucchesi have headlined the rotation's surprisingly hot start.

The recipe is simple. San Diego has received an infusion of talent from its top-ranked farm system. Around that talent, they've built a roster that should stay intact for the foreseeable future.

It's the endgame of a plan years in the making -- a plan that included serious financial commitments to Eric Hosmer and Manny Machado, along with a complete overhaul of the farm system.

And it all started with one incredible four-week stretch.

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As the calendar flipped from May to June in 2016, the Padres' outlook was bleak. Their system was depleted by an ill-fated run at contention the year before. Their roster was loaded with pricey veterans like Matt Kemp and James Shields, who offered little in the way of long-term help.

On June 2, the Padres reached the nadir, infamously blowing a 10-run lead to the Mariners at home. They fell to 21-34, 12 1/2 games out of first place without an obvious blueprint back to contention. To the outside world, San Diego needed something resembling a miracle.

"It didn't look like it, but we had a plan," said one Padres official. "But what good does it do to tell anyone you have a plan?"

The miracle materialized over the next four weeks, courtesy of the front office. Here's an incomplete list of the players the Padres acquired:

Fernando Tatis Jr.
Chris Paddack
Eric Lauer
Joey Lucchesi
Luis Patino
Adrian Morejon
Cal Quantrill
Hudson Potts
Buddy Reed

Here's what they gave up:

Fernando Rodney
James Shields
Amateur signing-bonus money

"That's always an active time, but that year was different," general manager A.J. Preller said. "We knew we needed to get talent into the system. We knew we were going to have an opportunity. We were prepared, we had done our homework.

"It was a matter of executing the plan."

Here's how Preller's plan unfolded:

June 4: James Shields for Tatis and Erik Johnson

Tatis has spent one week in the big leagues, and the trade is already regarded as one of the most lopsided in recent memory. It didn't seem that way at the time. Tatis hadn't played a professional game, and the Padres were eating a large chunk of the 2 1/2 years remaining on Shields' contract.

"It's always a risk when it's a player that had never played a game," Preller would later say. "But all the information basically came back the same way. We had a chance to get a very talented prospect. Even though he hadn't played a game yet, he should be a target."

He became the target. The White Sox were surprise contenders early in 2016, and their rotation was thin. With the Padres starting to sell, Shields was a fit. Preller initially asked for bigger name prospects, who were deemed off-limits. Tatis wasn't.

The White Sox did their best to hang on to the young shortstop. They knew he'd be good (though maybe not this good). Preller didn't budge, instead upping the Padres' offer to eat more than half of the remaining money on Shields' deal. Ownership signed off. Tatis and right-hander Erik Johnson became Padres. In every single story about the deal, Shields name appears first, and Johnson's name second.

But within a year, it was “the Tatis trade.” Solely because Tatis began to play. There's a legendary Arizona Rookie League game in which a 16-year-old Tatis singled in his first two at-bats, then stole second and third both times. In his third at-bat, he homered.

"That's when we really knew," said one Padres official.

June 9-10: Eric Lauer, Joey Lucchesi, Cal Quantrill, Buddy Reed, Hudson Potts, Reggie Lawson selected in MLB Draft

A year earlier at the Trade Deadline, Preller held on to Ian Kennedy and Justin Upton despite offers for both. The duo left via free agency that offseason, giving San Diego the first two comp picks the following June. In total, the Padres had six selections in the first 84, more than any other club.

Pro scouting director Pete DeYoung had already landed Tatis. International scouting director Chris Kemp was in the process of piecing together an elite class.

"Honestly, both of them just set the bar higher for us," said amateur scouting director Mark Conner.

Conner's team didn't disappoint. With the Kennedy pick, they drafted Lauer, who would become the second pitcher to reach the Majors from the entire class. The first? That was Lucchesi, a fourth-round steal the Padres eyed from the start. They'd have taken Lucchesi higher. But he was a senior from Southeast Missouri State who'd gone undrafted the previous year. The front office set Round 4 as the target, knowing full well Lucchesi wouldn't go off the board before then.

In the interim, they drafted Quantrill, Reed, Lawson and Potts, all Top 30 prospects currently in the system.

"As the Draft started to unfold and we started to piece things together, we began to get really, really excited," Conner said.

Even Conner couldn't have forecast so much production so quickly. Within three years, Lauer and Lucchesi are headlining the Padres' rotation. Quantrill could join them shortly.

"It's definitely exciting to see Lauer and Lucchesi already in the big leagues," Conner said. "But we're more excited to see what that group, as a whole, does over the next five years."

June 29: Fernando Rodney for Chris Paddack

One clear theme within the Padres' scouting department was the amiable competition among the three groups. Preller had given his international team, his amateur team and his professional team license to maneuver. He asked them to bring back as much talent as they possibly could.

"What was fun about watching this thing develop is that all three departments had an impact in different ways," DeYoung said. "My message to the pro guys was, ‘Let's make sure we're pulling our weight.’"

When DeYoung boarded a plane to Lexington, Ky., early that month, the Padres were already deep into discussions with the Marlins. Miami needed a closer, and Fernando Rodney still hadn't allowed an earned run all season.

"I didn't really know much about [Paddack], heard he was a guy to see, a guy that was throwing well," DeYoung said. "... I saw five innings, and he only threw two breaking balls the whole start. The fastball, the changeup, the mound presence, he had it all.

"That was a real quick call to A.J. This guy needs to be at the top of the list of targets for Rodney."

The scouts DeYoung sent to follow up were similarly glowing in their praise for Paddack. Within the month, the two sides had a deal. It was straight up. Preller, who knew he'd be making other moves, could afford to a take a risk on a Class A pitcher, just like he took a risk on a shortstop without any game experience.

Paddack tore his UCL a month later. He had Tommy John surgery and would miss the entirety of the 2017 campaign.

"That was a tough one to swallow," said DeYoung. "He hit the ground running with us. But you could see it in his meeting with us at the ballpark when he found out he was going to have Tommy John, the way he handled himself. He told us he'd be back."

He’d be back, indeed. Better than before. Paddack’s 2018 Minor League numbers were absurd. Over 90 innings, he struck out 120 hitters and walked eight. He won a job in the rotation this spring, well ahead of schedule.

July 2: Padres sign Luis Patino, Adrian Morejon, Jeisson Rosario, Tucupita Marcano, Tirso Ornelas

The Padres had legitimate interest in Yoan Moncada during the summer of 2015. Had they managed to sign the biggest prize from that year's international class, everything would've changed.

Instead, the following international signing period presented the Padres with a perfect confluence of three circumstances:

1. Big-spending clubs -- like the Yankees, Dodgers, Red Sox and Cubs -- had exceeded their bonus pools in the previous two years. They were hard-capped and couldn't offer more than $300,000 to any player.

2. The collective bargaining agreement was slated to expire that winter. Changes were expected to come to the process (and sure enough, teams were hard-capped the following year). The 2016-17 class marked the last chance for teams to spend exorbitantly.

3. Padres ownership committed to spending an unprecedented sum internationally. Including the 100 percent tax on teams that exceeded their spending pool, they spent approximately $80 million on international amateurs alone – more than double the next highest club.

Looking back, that class offers a useful lesson in international spending. The Padres were adding 16-year-old kids to the organization. No matter how talented the player, there's no such thing as a lock.

So they diversified and signed in bulk. A handful of their big-money signings became very good prospects -- namely Morejon and Arias. But the depth of the class was its strong point. Patino signed for $130,000 out of Colombia. Marcano went for $320,000 out of Venezuela. The organization views that duo in incredibly high regard.

The aftermath

The Padres' much-maligned 2016 farm system became one of the best in baseball by that offseason. By the following offseason, there was no longer any doubt. It was the best -- led by Paddack, Tatis, Lauer, Lucchesi, Morejon, Patino and so many others who were acquired that summer.

"That was effectively how this organization was rebuilt, that period in time," manager Andy Green said earlier this week. "The pieces are here right now. And more are coming."

Later that season, Preller was suspended for 30 games for his failure to disclose medical information in the Drew Pomeranz trade with Boston. It's undoubtedly an ugly mark on his tenure as general manager.

But his efforts during the rest of that year are starting to pay dividends. The 2016 Draft class made the first impact. The trade pieces are now joining the fray. Soon enough, the last-of-its-kind international free-agent class will arrive.

"I don't know if we could have envisioned the exact level to which they would help the organization," Preller said. "You're never that specific. But we knew we were signing, trading for, acquiring a lot of guys that were going to impact this club. Hopefully it pays off here in the next few years."

A week into the 2019 season, it already is.