In what other industry would millions and millions of pounds be essentially gambled on any one individual? Football is a world and a law unto itself in many respects, and no area of the sport identifies that more clearly than the murky realm of player transfers.
Every signing a team makes, especially a top-flight team in an established footballing country, is subject to intense analysis and observation. Selling a player from the first team is reduced to being a microcosm of a club's ambition, or lack of it, while every rumour reported in the media is discussed ad nauseum by fans on social media, forums and everywhere else online.
Transfers involve complicated negotiations more often than not, with four parties with vested interests all pushing to get the best cut of the deal on their end: the selling club, the buying club, the player involved and, usually, his agent.
But which holds the cards in concluding each deal?
Clubs, you would think, have a certain amount of say in each deal. After all, they hold the registration to the player and can simply refuse to sell him if they are not in agreement with any offer made.
While in principle this is correct, the reality is that clubs often feel pressured or forced into accepting bids for players which do not meet their full valuation.
There can be a range of reasons for this; pressure from the player or external influences linked to the player is just one, but the club's own finances is probably the biggest.
Can a League One side afford to hang on to a £1 million-rated player because a Championship side are only offering £700,000? Or a South American team keep a highly rated starlet because a Portuguese team won't offer the right conditions of sale?
Often the answer is no; the immediate injection of cash is more important to the day-to-day running of a team than holding out for the extra 20 percent which might never come.
In those instances, of course, the selling club will attempt to negotiate a range of clauses into the deal to benefit them if the player is increasingly successful; the buyer is more likely to agree to them, as they won't mind paying for a player who is coming up with the goods.
Sell-on clauses also help the selling club at an unspecified date in the future, where they could receive a percentage windfall when the player is sold on again to a new team.
At the other end of the scale, the super-rich clubs can afford to simply say no.
Take the instance of Carlos Tevez. The Argentinian forward simply upped sticks and left Manchester City midway through the 2011-12 season. He was repeatedly fined, of course, and was trying to engineer a route out of the club, but as no team matched City's sky-high valuation of what was, at the time, an elite top-flight striker, they simply opted to keep him and force Tevez to see out his contract.
With no other option, the striker returned to the team and played a part in a title victory, as well as staying another full season afterward before his recent departure to Juventus—at probably a third of the price his club were asking for, 18 months ago.
Such are the whims of those who can afford to say, "No deal."
Having multiple teams interested in the same player can lead to speculation that a "bidding war" is taking place.
Is that the case? Arguably not. Financial details on transfers are not often released, but it seems logical that if Team X bids Y million pounds for a player and has the offer accepted, then Team Z will simply come along and match it.
Perhaps the selling side will try to use this to their advantage, but it is unlikely to change the overall price of the player too much. It could be that the selling club gets to dictate terms a little more favourably.
The final decision for any particular transfer should, of course, rest with the player himself.
While teams have to come to an agreement on the financial aspects of a transfer, only the player himself can decide whether to move or not. He might already want to move, but he has the power to decline a transfer as well.
Nobody can force a player to sign a contract that he absolutely doesn't want to, even if the selling club is able to be somewhat persuasive by telling him he won't be involved in the team if he stays.
What is less fun for fans to deal with is when the player is actively pushing for a move. Take again the Tevez instance above; no supporter wants to hear that a star striker has moseyed off halfway through an important campaign to take in some sun and golf instead of giving their all.
Some players clearly pour their hearts and souls into a club, while others freely admit they play the game for money, not love, though all the while making clear that it doesn't make them any less professional.
Within contracts, players may have their own clauses inserted. If a Champions League team, for example, wants to sign him, he may be able to leave for a guaranteed price. It might be that he gains an extra season on his deal if he plays a certain number of matches or is released from his contract altogether if the team is relegated.
Of course, the players are not often the ones to put their demands directly to a club.
Some might not be confident enough with numbers; some might simply not have the first clue about what is supposed to be in a contract.
And there, of course, comes in the agent.
What does an agent do these days? Is he a businessman or a friend?
Read a top player's autobiography and it seems the lines are blurred at times.
The chief role seems to be to negotiate playing contracts, but some go far above and beyond. Searching out commercial sponsorships, taking care of property, helping arrange for everything from personal purchases to telling the player when he should leave the club—the power some agents appear to have over players verges on the scary.
Like in all walks of life, there are agents who are more well-known than others and appear to be far more successful at concluding the big deals for big money.
Pini Zahavi is probably more of a recognisable name than half the national team of his native Israel, while Jorge Mendes and Mino Raiola are mentioned in pretty much every national newspaper, every week, while the transfer windows are open.
Stories emerge every year about a player actively seeking new representation from specific agents to help conclude a transfer to a specific club, moves which help the new agents generate thousands, perhaps millions of pounds from a single deal.
There is a train of thought that agents should represent clubs rather than players to ensure that everybody at one team gets equal treatment. It's an interesting idea, but one that the existing agents themselves would likely reject, and probably also the players.
A player, even if he likes a club, wants to feel that he is getting paid his true worth and trusts his agent to negotiate on his behalf. Having an employee of the club tell the player what he is worth is probably not going to appeal quite as much.
There is clearly a role for the agent in modern-day football transfers, but again, it is the actions and the ethics of a select few which seem to cause the most strife. Rumours planted purposefully to generate interest or pressure a club into selling, or offering higher wages, are now commonplace, though no more agreeable.
Third-party ownership. Co-ownerships between Italian teams. Loan deals with options to buy, sales with options to buy back, part exchanges and who knows what else.
There are also work permits to consider when players are coming into the United Kingdom, and the rules to which teams have to adhere to receive one are not always clear-cut.
All in all, there is no one set way that transfers have to be processed. The variety and lack of clarity makes things incredibly stressful for all involved—not least the fans, who wait in the modern age of instant technology for days upon days, hoping at last to see "confirmed" alongside the names of players their team have been linked to for weeks.
In any given transfer, all three parties have a role to play and have an amount of power.
Length of contract is a hugely difficult factor to take into account; in an age of Bosman transfers, three years left on a deal is an eternity, two a balancing act between taking the big money and letting the contract run down, and one year remaining almost certainly equals a massive reduction in asking price.
At that point the balance of power seems to shift firmly toward the player, though again, specifics such as his age and position will all play a part.
The next two months will provide many more indications of just how complex the nature of transfers are in world football, with deals dragging on for days or weeks before a successful conclusion.
For supporters, the only thing that matters is the squad lists at the end of the window. For clubs, players and agents alike, an awful lot of telephone calls, meetings and skilled negotiations have to go into each deal just to make a move happen.
It's a balancing act, one which shifts on a window-to-window basis with each potential transfer, and one which isn't going away anytime soon.