By Simon Kuper and Stefan Szymanski 
Much of conventional soccer “wisdom” (like other sports) is wrong. [Editor’s note: I would argue that these points apply to other sports as well.]
Cliche #1: Soccer is just big business these days.
Actually soccer isn’t, and never has been, big business. Most clubs have the revenue of a grocery store. Not a grocery chain. A single grocery store.
And they aren’t even run like a business. Statistical analysis shows that if teams were trying to maximize profit, they could do so by cutting payroll and sacrificing wins. For example, FC Barcelona would be most profitable if it cut payroll to the point that they would likely finish in 15th place.
Cliche #2: My club desperately needs a new manager.
Actually, managers don’t usually matter all that much to a team’s success. [Editor’s note: while I think this is true, no general data was provided to support this assertion, just a single example].
Cliche #3: My club desperately needs some high-priced free agents.
Actually, free agents are usually dramatically overpaid. This is because teams pay them based on their stellar playing histories. However, by the time a player has achieved that level of success, their skills are already starting to decline.
Clubs should buy players in their early 20s. They are cheap and they are still getting better. Players in their teens, no matter how spectacular, are not worth much money because they seldom pan out.
A much better strategy is to spend a lot on your overall payroll, rather than on a few free-agents. There’s almost a 100% correlation between a club’s total payroll and its league position (in the long run).
Cliche #4: Players from poor backgrounds are hungrier for success.
More likely is that it has to do with Malcolm Gladwell’s “10,000-hour rule”, which says that any performer must practice at least 10,000 hours to become world class. Poor kids live in cramped apartments, so spend time outside with friends in similar circumstances. Since they can’t afford many leisure activities, they play sports that are basically free, like soccer. Their modest upbringing allows them the time to become great soccer players.