You have to admire Borussia Dortmund. Not only do they play liquid football and hand youngsters a chance, but they also boast one of the most fruitful scouting networks in world football.
Over the years BVB have churned out world class star after world class star, but more often than not, those blooming talents have left the Ruhr district after being offered unimaginable riches from Europe's super-clubs.
Despite having their ranks pillaged on an almost annual basis, Dortmund have not yet slipped into anonymity, instead they have continued to produce batches of elite quality to rival the very best.
Some of the biggest transfer deals have involved BVB, though very rarely are the German club on the buying end, instead they have accrued some of the most lucrative fees in world football. They've managed to keep this business model sustainable by not then squandering the money on marquee signings or headline acts, but rather, shrewd — sometimes under the radar — investments.
A quick glance at Dortmund's current frontline will tell you there's at least three future Ballon d'Or contenders. One was signed for under £20m in January (Erling Braut Haaland), one came through the academy (Giovanni Reyna) and one was plucked from Man City for a reported £8m (Jadon Sancho).
Of course, BVB are not immune to the odd slip-up here and there. Not all of their replacement signings have hit it off like Sancho. Here, we look at the judgment calls they've made after some of their recent big-money transfer sales.
Sold: Sokratis Papastathopoulos to Arsenal (£17.6m)
Signed: Abdou Diallo from Mainz 05 (£25.2m)
Season: 2018/19 (summer)
Sokratis joined Dortmund following their impressive run to the 2013 Champions League final. BVB, with Jurgen Klopp at the helm, would establish one of European football's defining central defensive partnerships in Mats Hummels and Neven Subotić, so it seemed only natural the Greek international would have to bide his time.
But this wasn't the case. A combination of factors enabled Sokratis to cement a regular berth in Klopp's starting line-up, and he would continue to feature under the current Liverpool manager's successors – Thomas Tuchel, Peter Bosz and Peter Stöger – before leaving for Arsenal two summers ago.
Dortmund's record in recruiting centre-backs isn't too shabby. Sokratis, who served the Die Borussen well, essentially made way for Abdou Diallo, who joined from Mainz 05 – the same club as Subotić.
The 24-year-old would spend just one season at Dortmund, though, featuring in 38 games across all competitions in 2018/19 before signing for French powerhouse PSG last summer. And of course, Dortmund made a profit.
Verdict: Hit
Sold: Ousmane Dembélé to Barcelona (£96.8m)
Signed: Jadon Sancho from Manchester City (£8m)
Season: 2017/18 (summer)
Everyone has a price in football, and when Barcelona were prepared to spend nearly £100m on acquiring the services of Ousmane Dembélé, soon after they had lost Neymar to Paris Saint-Germain for a world record fee, BVB weren't going to stand in his way.
Truthfully speaking, the relationship between Dembélé and Dortmund had broken down, so a transfer was always on the cards. It was a sad end to what promised to be a fruitful partnership.
As he packed his bags for sunny Spain, arriving to inherit Dembélé's 'number seven' jersey was teenage English forward Jadon Sancho, who also caused a stir in the way he departed then parent club Manchester City.
Sancho's reasoning for the move was simple; Dortmund guaranteed a fast track to first-team football – thus accelerating his development – something that has proven to be difficult for a number of City academy graduates down the years.
Such was his incredible start he relegated Pulisic to a squad role before the US international signed that blockbuster deal with Chelsea. And since then Sancho has gone from strength to strength, recently hitting his first senior hat-trick at the weekend to bring up 20 goals and 20 assists for the season. An inspired signing.
Verdict: Hit
Sold: Pierre-Emerick Aubameyang to Arsenal (£56m)
Signed: Michy Batshuayi (loan) and then Paco Alcácer (loan)
Season(s): 2017/18 (winter) and 2018/19 (summer)
Pierre-Emerick Aubameyang joined BVB to great fanfare in 2013 but exited amid controversy in January 2018.
The 30-year-old Gabonese marksman's record, though, speaks for itself. Aubameyang, across 213 appearances, bagged 141 goals in all competitions and finished the 2016/17 season as the Bundesliga top-scorer.
However, disciplinary issues plagued his final months at the club, and in January 2018 he swapped North Rhine-Westphalia for north London to join Arsenal.
Aubameyang ultimately replaced Olivier Giroud, who left for Chelsea, a move that saw Michy Batshuayi (albeit on loan) fill the space vacated by Arsenal's 'number 14'.
Batshuayi made up for Aubameyang's lost goals by scoring nine times in 14 appearances, before returning to England. But it would be the signing that followed that can be deemed as Auba's successor.
Paco Alcácer struggled for playing time at Barcelona and viewed Dortmund as somewhere he could get his career back on track. Despite never really cementing a consistent starting berth, the Spaniard's scoring record was immense. In 17, yes 17, Bundesliga starts, Alcácer bagged 23 goals, and he later left for Villarreal, becoming the club's most expensive signing last summer.
Verdict: Hit
Sold: Matthias Ginter to Borussia Mönchengladbach (£15.3m)
Signed: Manuel Akanji from FC Basel (£19.3m)
Season: 2017/18
Big things were expected of Matthias Ginter when he joined Dortmund from SC Freiburg in the summer of 2014.
The promising German centre-back was earmarked for the future but remained at the Westfalenstadion for three seasons before joining Borussia Mönchengladbach, where he continues to fulfil his talents.
His exit saw Dortmund move in the market and they acquired the services of FC Basel central defender Manuel Akanji, who is first choice on Lucien Favre's team sheet when available.
Akanji has formed an indispensable part of Favre's unconventional backline this season, playing on the left of centre-back trident consisting of Mats Hummels and stalwart Lukasz Piszczek.
Verdict: Hit
Sold: Mats Hummels to Bayern Munich (£30m)
Signed: Marc Bartra from Barcelona (£7.2m)
Season: 2016/17
It's never easy losing a key player to a rival, especially when that individual was on course to become a club legend. Mats Hummels symbolised BVB's renaissance under Klopp so to join Bayern, the boogeyman, was a kick in the proverbial teeth.
Hummels was there for their incredible back-to-back championship triumphs, subsequently announcing himself as one of Europe's finest central defenders, before playing a pivotal role in reaching the 2013 European Cup final.
Bayern won that day and soon after purchased Mario Götze, Robert Lewandowski (on a Bosman) and Hummels.
Marc Bartra, tipped for stardom during his Barcelona youth days, was supposed to ease the pain. For a while, he did just that but could never live up to the billing and following a difficult final campaign (2017/18) returned to Spain.
At least Hummels has returned.
Verdict: Miss
Sold: İlkay Gündoğan to Manchester City (£20m)
Signed: Sebastian Rode from Bayern Munich (£12.6m)
Season: 2016/17 (summer)
Dortmund's reputation for developing footballers is now world-renowned. Gündoğan, who joined from FC Nürnberg in 2011, went from a prospect to a great example of a modern 'number eight'.
The native of Gelsenkirchen soon attracted many admirers but remained loyal to BVB before feeling it was time. One reason he never had an exit on his mind was how the club treated him during his numerous spells on the sidelines.
A healthy Gündoğan is only matched by a few. Manchester City can attest to this as the Germany international overcame a jittery start to become one of Pep Guardiola's most influential players in the middle of the park. The same, unfortunately, could not be said of Dortmund's replacement.
Rode, to put it plainly, was a huge disappointment. He came with much promise but offered very little, and is now battling it out near the foot of the table with Eintracht Frankfurt.
Verdict: Miss
Sold: Henrikh Mkhitaryan to Manchester United (£30m)
Signed: Ousmane Dembélé from Rennes (£13.5m)
Season: 2016/17 (summer)
Mkhitaryan enjoyed his best season for BVB prior to joining Manchester United.
The multifunctional Armenian forward created no fewer than 20 goals across 31 Bundesliga outings, thus earning the accolade of 'assist king', but he was never able to replicate that at Old Trafford.
But what of his replacement? Well, he's been somewhat more of a success. Mkhitaryan, who can play just behind the centre-forward, nominally operated wide in his final campaign.
Dortmund signed André Schürrle and Ousmane Dembélé that summer, though it was the latter who played the most minutes and made the biggest impression.
Verdict: Hit
Sold: Mario Götze to Bayern Munich (£31.5m)
Signed: Henrikh Mkhitaryan from Shakhtar Donetsk (£22.5m)
Season: 2013/14 (summer)
This one really hurt. Mario Götze, seen as the club's golden child, soon after BVB reached the 2013 Champions League final made it known he was going to join Bayern that summer.
The revelation took everyone by surprise, including manager Klopp, who done well to compose himself. Up until that point, Götze was Dortmund's heart and represented a new breed of playmaker.
To say the supporters were angry is an understatement. As the former Golden Boy exited, BVB welcomed Henrikh Mkhitaryan from Shakhtar Donetsk.
And as soon as the Armenian was settled, Götze was forgotten. His time at Bayern, meanwhile, wasn't all sunshine and the German international returned home the summer Mkhitaryan departed like two ships passing in the night.
Verdict: Hit
Sold: Shinji Kagawa to Manchester United (£12m)
Signed: Marco Reus from Borussia Mönchengladbach (£15.4m)
Season: 2012/13 (winter)
Kagawa was a true success story. Signed from humble origins, the Japanese playmaker would turn out to be BVB's secret weapon in their championship triumphs under Klopp.
If anyone represented the club's excellent transfer strategy, it was him. For decades Asian footballers have made Germany their home and Kagawa followed in the footsteps of his predecessors.
However, as we've come to know, the attention generated by success can lead to doomed career moves. Manchester United saw Kagawa as the creative solution their midfield was crying out for. Though, despite winning a Premier League winners medal, he never really found consistent momentum at Old Trafford.
He would return — like Hummels and Gotze — and link up with the man who had initially replaced him. Marco Reus, who came through BVB's youth set-up and left before making a name for himself at Gladbach, would make up for lost time. Now the club's most influential player (when fit) and captain, there is no question Reus is a hit.
Verdict: Hit
Sold: Christian Pulisic to Chelsea (£58m)
Signed: Thorgan Hazard from Borussia Mönchengladbach (£22.5m) and Julian Brandt from Bayer Leverkusen (£22.1m)
Season: 2019/20 (summer)
The American wunderkind officially completed his move to Chelsea in the winter window of last season but stayed on loan with BVB until the summer, where he relocated to Stamford Bridge permanently and Dortmund sought to replace him.
The Hershey-born winger was a trick and a treat during his time in Germany, regularly leaving full-backs befuddled with his deceptive movement, while also delighting those in the stands. When he has been fit and available, Chelsea fans have enjoyed a similar experience.
But, like many on this list, Dortmund refused to rest on their laurels and feel sorry for themselves when their latest boy wonder packed up and left. Instead, they used that money to sign coveted duo Hazard and Brandt — and they still had over £10m left over.
This season both players have slotted in fluidly to Favre's system and are really coming to the fore as Dortmund currently sit second in the Bundesliga. Hazard has seven goals and 13 assists to his name, while Brandt has three goals and five assists. Certainly money well spent.
Verdict: Hit
Sold: Paco Alcácer to Villarreal (£19.4m)
Signed: Erling Braut Haaland from RB Salzburg (£19.2m)
Season: 2019/20 (winter)
As far as stopgaps go, Alcácer was as good as they got for Dortmund. He was never expected to guide the club to stratospheric heights, but he certainly remedied the great goalscoring void of Aubameyang during his time in Germany, and that is no small feat.
But, Alcacer served his purpose for BVB and they soon turned their attention to unearthing the next iconic No. 9, someone who could really come in and make the sort of impact Aubameyang made when he first burst onto the scene from Saint-Etienne. Enter precocious goal fiend Haaland.
Dortmund deserve a huge pat on the back for selling Alcacer for £19.4m and buying Haaland for a fee just south of that, despite most — if not all — of Europe's elite clubs circling Salzburg like a swarm of bloodthirsty vultures.
Haaland will receive no greater education than that at Dortmund, and he has already shown why he was grabbing all the headlines in Austria. Thus far the young Norwegian has bagged 13 goals and three assists in 14 games for his new club.
He looks the full package already and the scary thing is, he is still only 19. The limits are boundless.
Verdict: Hit