It was bound to happen once financial regulations -- like the Premier League's Profit and Sustainability Rules (PSR) -- were tightened. Accounting principles, and the ability to exploit them, become important to teams, like hiring a scout who can unearth a teenage prospect. And so you end up with de facto swap deals that don't look right to most observers.

We'll get to how they work in a minute, but there are two things to bear in mind here.

The first is that, at least regarding the cases we've witnessed in the Premier League -- Tim Iroegbunam and Lewis Dobbin between Everton and Aston Villa; Ian Maatsen and Omari Kellyman between Chelsea and Villa; Douglas Luiz and Samuel Iling Jr and Enzo Barrenechea between Villa, again, and Juventus -- aren't examples of cheating. Rather, it's simply working the system and the letter of the law, and whatever benefit the clubs get now will have to be accounted for down the road. You're not "cooking the books" and generating money out of thin air in perpetuity. Though the Premier League reportedly wrote to all 20 clubs last week to warn them that such transfers will be scrutinised.

The second is that there are mechanisms to prevent the most egregious excesses, some of which are already in play. And in any case, if you believe in wanting clubs to be financially sustainable because it's good for the game's entire eco-system, a summer or two of "funny" transfers is a price worth paying. It's a sign that clubs are taking regulation seriously, perhaps after seeing their brethren (namely Nottingham Forest and Everton) punished with points penalties this past season.

What regulations are we talking about? Well, the Premier League has PSR, which limits the losses a club can accrue over a three-year period. Some expenses -- infrastructure, youth development, women's football -- are seen as "virtuous" and aren't included in the calculation, but without getting overly technical, the point is this: there's a ceiling to how much each club can lose over a rolling three-year period and if they go above it, they get punished. And because most clubs' accounting periods end on June 30 each year, if your books aren't great, there's an incentive to shift players for a fee before July 1 in order to comply with the loss limit.

(It's worth noting that UEFA has its own set of regulations -- actually, multiple sets of regulations -- for clubs playing in European competitions like the Champions League, but we'll leave that to one side for now.)

The easiest way to raise money quickly in football, of course, is moving players out for a transfer fee. The only problem is that your players are generally worth whatever someone wants to pay to sign them, and because acquiring clubs know which clubs are in need of raising funds, are and the transfer window doesn't close until Aug. 31 -- which means there's little "panic shopping' in June -- it's hard to maximize your fee if you try to move a player early in the summer.

Enter the "swap deal," which may sound funny and may appear like some sort of book-keeping sleight of hand, but is actually in line with accounting practices. It hinges on the fact that when you transfer a player out for a fee, that fee gets booked as profit straight away, whereas when you acquire a player, the transfer fee gets spread out over the life of the contract.

We'll use the grand-daddy of them all -- the Miralem Pjanic for Arthur swap between Juventus and Barcelona -- to illustrate the point.

Using figures from the excellent Swiss Ramble blog, Barcelona acquired Arthur in 2018 for 30 million and gave him a six-year deal, meaning that 5m of that cost would be on their books each year until 2024 (a concept known as "amortization.") In 2016, Juventus signed Pjanic for 35m and gave him a five-year deal, followed by a two-year extension, in 2018. That meant that when the Arthur-Pjanic swap took place (in 2020), Arthur's transfer had a book value of 20m (the residual amortization on his fee) while Pjanic's was 13m (due to the two-year extension spreading things out further.)

At this point, Juventus transferred Pjanic to Barcelona for 63m, while Arthur went the other way for 72m. It allowed Barcelona to book a profit of 52m (72m minus his book value of 20m) and Juventus to book a profit of 50m.

That was one of the more extreme cases. Today, folks look at deals like Iroegbunam (21 years old, with 164 league minutes in 2023-24) moving to Everton for a 9m fee, while Lewis Dobbin (21, with 232 league minutes in 2023-24) goes the opposite way for 10m and see something similar going on.

Officially, these are entirely separate deals that just happen to occur around the same time. But based on the fact that both players had a negligible book value and that Iroegbunam was given a three-year deal (therefore his 9m fee costs 3m a year), Swiss Ramble estimates that Everton made a cool 7m off that deal. Dobbin's contract length wasn't reported, but assuming he got four years (so 2.5m in amortization), then Villa get to book a 6.5m profit.

Some will be up in arms at what they see as nothing more than accounting chicanery. To most normal folk, the idea that you can just trade two players in their 20s who probably won't have meaningful top-flight careers and generate millions out of thin air seems somehow wrong.

There are a few things worth pointing out here. First, while players no doubt appreciate the concern over their humanity, the fact is their employers run a business and treat them as productive -- and depreciating -- assets, like a farmer with his new tractor. And that applies in U.S. sports too, by the way, which is why older tractors who cost a lot to run (i.e. stars on expensive contracts) sometimes get traded for the right to pick up a shiny new tractor at the county fair (or NFL draft.)