The transfer window can be the best and worst time as a soccer fan: either your team is linked to every top player and they eventually make some signings, or they're left settling for some last-minute loan deals to remain competitive. There are rumors, whispers and endless paper talk. There's also a lot of jargon to keep you confused.

Who sets a transfer fee? Is a "free" transfer really free? How do clubs offset the costs of doing business? What does an intermediary do and why do teams need them, anyway?

ESPN FC senior writer Gab Marcotti shines a light on the transfer market and explains it all.

Q: All those transfer stories out there ... it's just made-up clickbait, isn't it?

A: Some of it, sure, and some of it may not be made up in the sense that there is a source, just perhaps not a credible source or a second-hand source. When you see stuff attributed to other publications, it means the publication you're reading hasn't been able to verify the story but there's some level of credibility to it, so they attribute it to somebody else.

Some stuff has a source, but it's an interested party. For example, a club or an agent may tell reporters on background that they had interest for Player X from Clubs Y and Z. It may or may not be true, and the reason it might not be true is that it could be an attempt to drum up interest in Player X. An educated reader needs to make up his own mind about the credibility of the publication and the individual reporting it.

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Another situation that regularly occurs is that a story may appear in one country on Tuesday and then get picked up by a publication in another on Wednesday. And then, on Thursday, the story will reappear in the original country with the presumption that the other media outlet offered "confirmation" of the story when, in fact, all they did was repeat what had been originally published. That used to happen a lot in the past -- less so now thanks to the internet and the 24/7 news cycle.

But there are plenty of stories with solid reporting behind them too.

Q: Yeah? Well what are the sources?

A: People don't realize that in the transfer ecosystem, there are plenty of folks who know what's going on. Some have the full picture, others only part of it, but there are plenty who talk. Players have family members, friends and teammates who talk. There are directors of football, scouts and managers who talk. And, of course, there are agents and intermediaries who talk.

Q: Why would they? Wouldn't it make more sense to keep things confidential?

A: It depends on the situation. Many clubs have press officers whose job it is to provide information to media, a way of controlling the message. Sometimes they don't comment on certain subjects, sometimes (rarely, to be fair) they flat-out lie, sometimes they tell you what's going on. And even when press officers don't do that, others at the club will because it's immaterial to the deal.

Take Manchester United's reported interest in Aaron Wan-Bissaka: the story is out there whether they make another bid or not or, indeed, how much they bid isn't going to impact whether he joins or not. The same applies to agents. The clever ones know when to talk and when to stay quiet.

Sometimes a club may want to put information out there to keep the fans happy. It shows that they're trying to do something, it gets their brand in the headlines, and sometimes, it can accelerate a deal.

The best example I can think of involves Argentina striker Gabriel Batistuta. In the summer of 2000, Roma were looking for a center-forward but were quoted what the club thought was an insane price for Fiorentina's Batistuta: more than $40m for a 31-year-old striker. (It's a big number even today and back then, even more so.) Club owner Franco Sensi decided it was far too much so Fabio Capello, Roma's manager at the time, told a newspaper that the Batistuta deal was on the verge of going through even though Sensi had said "no." When it appeared in the paper the next day, Sensi's phone started to ring off the hook with well-wishers congratulating him on showing so much ambition. Fans sang his name in the streets. He was suddenly a hero for breaking the bank and, eventually, he agreed the deal. Roma won the title the next season.

That said, there are plenty of other occasions when at least one party in the deal wants to keep things under wraps. Fortunately, in any transaction, there are multiple parties and rarely is it in everyone's interest not to talk. In fact, very rarely is it in the interest of intermediaries not to talk.

Eden Hazard's move to Real Madrid finally went through but not before plenty of speculation, paper talk and intermediaries putting info out through the newspapers. Angel Martinez/Getty Images

Q: Run me through what these guys, intermediaries, do again? Why can't clubs just talk to each other?

A: Simply put, intermediaries do things clubs can't, like approach a player (via his agent) without his club's consent, which is technically illegal. Before you make an official approach and offer a hefty sum for a player, you want to know how much it will cost you in terms of wages and contract length. That's something the intermediary can do on your behalf: he or she can also make the initial approach with a club to get an idea of what the asking price might be.

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It works in reverse, too. If there's a player you might want to sell, whether to upgrade a position or to raise cash, you might employ an intermediary to get the word out. Or, sometimes, his agent will be doing the same. It helps a club maintain plausible deniability towards fans (who might not want to see a star player sold) and towards the player himself, since nobody likes to be told they're considered surplus to requirements or simply not good enough. Not to mention the fact that the minute you stick a "for sale" sign on somebody, his price drops.

Q: OK, so what determines a transfer price? It's a free market so it's whatever a club is willing to pay, right?

A: Not quite. In fact, terms like "going rate" or "market value" are pretty meaningless. There are forces you'd expect to determine a player's price: talent, age, nationality -- a guy with an EU passport or, better yet, who satisfies association-trained or home-grown requirements is worth that much more -- current wages and length of contract. But at the higher end of the market, these factors often get distorted. Top talent is rare and clubs often believe (whether rightly or wrongly) that only a certain player will do.

Take Eden Hazard. Real Madrid paid around $110 million plus bonuses. That doesn't mean they would have been just as happy with 11 guys costing $10m each (plus bonuses). Players aren't commodities in that sense.

Another example is that the price ends up being intrinsically linked to the urgency of the buying club. After Neymar left Barcelona and joined PSG for around a quarter of a billion dollars, the Catalan club found themselves sitting on a pile of money and desperately needing a winger. They spent some $120m of it on Ousmane Dembele from Borussia Dortmund. He's a fine player, but it's a safe bet that if they had tried to buy Dembele at the start of the transfer window rather than at the end, they would likely have spent half as much. Timing can make a difference.

It also matters which club is doing the buying. In the summer of 2016, Rennes sold central midfielder Abdoulaye Doucoure to Watford for around $12 million. A bigger, wealthier club were also interested and had offered $20m for the player, who was their second choice to fit in midfield. But because that bigger club got their first choice, Watford were able to secure Doucoure for 40 percent less. This sort of thing happens all the time. The lesson is simple: it's very difficult for wealthy clubs to acquire players without sellers jacking up the prices.