Football's increased commercialisation has forced a clear shift in how we measure the achievements of our clubs. In the past, this was done simply by totting up the number of trophies won, success often breeding further success as players were attracted by the possibility of glory and fame.
Money, however, has indelibly altered that concept. Winning the highest-profile silverware is still the ultimate aim, but the phrase 'buying success' has entered football's lexicon, and ten years ago no-one was smugly ending their case for a footballing defence with the words 'net spend'. In contrast with yesteryear, the vast majority of clubs now begin each season with a definite ceiling on what they can hope to achieve, simply because the financial power of those above them imposes a limit.
Measuring success now is not simply a case of looking at who won what, but instead requires an assessment of an achievement vs. spending ratio. This is the reason that Swansea's Michael Laudrup and West Brom's Steve Clarke deservedly received notable praise for their achievements last season, and was the largest factor in the sacking of Roberto Mancini at Manchester City - yes, he won trophies, but just look at what he spent.
This is understood by those in the game. Since the turn of the century no manager has won the LMA Manager of the Year award (voted for by all Football League managers) more often than David Moyes, and only five of the 20 winners have been managing the Premier League champions.
A football club's nirvana, therefore, is to skew the achievement vs. spending ratio significantly in its favour, maximising success without outlandish outlay. This is the principle on which the Borussia Dortmund love-in is understandably based, because the German club have made €35million in transfer profit since 2010, whilst winning two Bundesliga titles, the German Cup and reaching the Champions League final.
However, Dortmund don't even come close to European football's biggest success story. Since 2002, FC Porto have won nine league titles, five Portuguese cups, seven domestic Supercups, two Europa Leagues and a Champions League.
Whilst that honours list is impressive, the true story lies in Porto's transfer record over that time. In ten seasons, Porto have sold players worth €554m, making a profit of over €270m, or close to €30m per season. In addition, they have recouped around €20m for the release of two notable managers - Jose Mourinho and Andre Villas-Boas.
Their roll of honour is breathtaking. Ricardo Carvalho €30m, Paulo Ferreira €20m, Deco €21m, Maniche €16m, Pepe €30m, Anderson €32m, Ricardo Quaresma €25m, Jose Bosingwa €21m, Lisandro Lopez €24m, Bruno Alves €22m, Hulk €40m, Falcao €47m. I really could go on.
A club's ability to sell, on average, more than €50m worth of talent every summer over an extended period is phenomenal, but to do so whilst continuing to maintain achievement is unprecedented. Put simply, Porto have cracked it. They have come as close as anyone to achieving football's economically warped version of Oakland Athletics' Moneyball.
Porto's incredible record is based on their commitment to two distinct ideals. Neither works efficiently without the other, but together they create the breeding ground for profit to be coupled with the realisation of on-field aspirations.
Firstly, the club's scouting network is almost unsurpassed worldwide, and is particularly strong in South America. Director Antonio Henrique explains further: "We work with 250 scouts around the world in countries that make sense for football, because we will not send anyone to Bangladesh. We have internal and external scouts, which are divided into several levels of observation, which allows a player to be viewed by several people. They work with a shadow team, which is a set of players who are identified from various leagues, who are capable of being hired by Porto."
Using such a system, Porto have been able to generate significant profit on almost every player they have purchased. Monaco may have made a statement this summer with their recruitment of Joao Moutinho, James Rodriguez and Falcao, but Porto made a profit of approximately €97m on selling the three players (Falcao was sold by Porto to Atletico Madrid). Clearly having Jorge Mendes clients (as I discussed last week) also helps in ensuring rather over-inflated fees.
A thorough scouting network evidently means that players can be bought before potential has been realised, and, crucially here, for lower fees. Porto have bought just four players for more than €10million in their history (as a comparison, Chelsea have bought 43, Manchester City 31, Liverpool 26, Manchester United 24, Arsenal 23). Three of those have been sold at considerable profit, whilst 21-year-old Brazilian Danilo remains at the club, already attracting rumoured interest from Barcelona and Chelsea. You would have thought that clubs may have worked it out by now, but it appears not - rather than buying from Porto, why not put more effort into doing as they do, investing more money into recruiting the best scouts, and then trusting their judgment, cutting out the middle man?
The second element in Porto's success is their on-going commitment to providing young players with the opportunity to shine. Although Portugal has a clear pull factor for Brazilians (lack of language barrier) and other South Americans (relaxed migration laws and an opportunity to easily gain an EU work permit) the club's propensity to blood in young players has led to them being the attractive option for youth talent, who can be confident that they will develop before having the opportunity to move to bigger clubs.
This youth ethos is described by the club's chairman Jorge Nuno Pinto da Costa: "We have to be permanently studying the youth market. This is what allows us to keep fighting, despite having a budget 20 times less in respect to income than others. Players come here and feel at home straight away."
Such a plan negates the potentially damaging effect that the departure of star names could have, neatly demonstrated by the club's key central defenders throughout the last decade. Jorge Andrade left for Deportivo in 2002 and Ricardo Carvalho stepped in. From Carvalho to Pepe. From Pepe to Bruno Alves. From Alves to Nicolas Otamendi. If Otamendi leaves this summer, 21-year-old Brazilian Alex Sandro will step up. All players sold, all immediately replaced without negative impact.
The same has occurred in attack. Derlei left for Dinamo Moscow in 2004, and Luis Fabiano stepped in. From Luis Fabiano to Lisandro Lopez. Lopez to Falcao. Falcao to Hulk. Hulk to Jackson Martinez. Throughout the squad the same is occurring, essentially creating a conveyor belt of talent ready to step into the breach. This is a revolution of footballing evolution.
It might just appear to be sound logic to you, but no other European club is using the transfer market to such efficiency, and there is no other squad that could lose multiple star players season after season and continue to have ready-made recruitments.
As Financial Fair Play (FFP) rules begin to bite, make sure you scorn and scoff at those sides that bemoan the effects of having to live in something approaching financial reality, because clubs such as Porto may be finally recognised for their achievement. It may be a while before they win the Champions League once again, but theirs is European football's real high-profile success story.
Daniel Storey - follow him on Twitter