I think you see Fantasy Football and NFL a bit muddled, Tatts
Basically, NFL teams, unlike soccer teams, don't have youth academies.
Instead, the players advance from the school system. A player usually starts playing football in high school teams. When he graduate from High School and he is good enough, the college schools try and recruit the best of the crop who then play as amateurs for the college (There's a huge scandal about Oklahoma's recruitment currently, and the Texas A&M quarterback Manziel faced a lot of flak for selling autographs, which is seen as income generated by playing football and therefore not amateur-worthy).
When a player deems himself ready (but only after advancing a certain amount of years/classes/whatever), he can decide to make himself draft-eligible, which means that he wants to pursue a pro-career. The draft is a once-a-year event that sees all NFL teams (theoretically) pick 7 players in 7 rounds, each round starting with the worst team and ending with the year's Super Bowl winner.
So the year's worst team has the best choice, and the year's best team will get a 'lesser'/more risky player.
It is the only real youth-intake (although teams can sign players who weren't drafted - but these are
usually not the top talents... Tony Romo, the Dallas Cowboys QB, is an undrafted player, for example).
Every once in a while, a team can get an 'extra' pick from the league if they lost a lot more players due to contract expiration than they got in free agency (and sometimes, the League takes picks as penalties for teams, as happened to New Orleans), but with 32 teams and 7 picks each, theres's an intake.
There's also a set of rules of how contracts for newly selected players must look, AND the league sets salary limits each year, which teams can not go over.
However, the above only goes for
new NFL players. Players who already had a contract can only leave teams when their contract runs out, or when their current team trades them to a new team - and the new team will take over the exact contract obligations and not a penny more.
This is all intended to make the NFL as fair as possible, to prevent situations like in the Premier League, where Manchester City has five times the salary scale and the spending power of Southampton and thus will beat Southampton 9 times out of 10.
It also allows team owners to run their teams as profitable businesses, where in soccer the trend is for teams to go in debt/spend all they get in to get higher up the table.
It also means that identifying player potential and paying the right players the right amount of money becomes super important as the only way to do better is to have a guy contracted whose value is above what you pay him: if you succeed in that, you can have more quality players in your team than if you overpay several players, as to compensate for them, you need to get smaller contracts and that usually means worse players. The only time teams will want to overpay is if the player fills in an essential need in your team (like quarterbacks).
Fantasy Football simulates the draft and player trading partly. We pick in a top-to-bottom order and then do a snake draft to not give too much of an advantage to the team that picks first (otherwise, Obdi would not only get the player he judges best, but each time the player he deems the best for his roster from all remaining players - in this way, he gets the best and then has to wait until everyone else has their second-best choice before he gets his second... so technically he gets the nr 1 and nr 24 player, instead of the nr 1 and the nr 13 player, which is a big difference).
Everyone is entitled to his own wrong opinion. - Lizrad