So how does the draft work exactly? Can anyone throw their name into the hat? Is there some age restriction at play? And how do clubs decide whom to pick? How is it different from signing an arbitrary player in the middle of a season?
Let me try to explain this without confusing you or me in the process.
The draft is the primary way to which NBA clubs acquire new talent. Nearly every player that has ever played in the NBA has come in through the draft process.
Here is how the current rules apply. A player, in order to be draft eligible, has to be at least 1 year out of high school, whether that means playing one year of college basketball, or playing overseas on a professional club.
The order of the draft, and how it is determined is done two ways.
First, there is a draft lottery for the 14 clubs that did not make the playoffs. The order of selection for the lottery is determined by ping pong balls. Yes. Ping pong balls. The worse record you have, the more ping pong balls you have in order to get the top pick. There are opportunities for teams to move up at the expense of another club's projected draft slot. For instance, the Lakers had the 4th worst record this year, but moved up to #2 in the Lottery, and the knicks conversely moved back from #2 to #4. The draft order for the lottery is determined shortly in advance of the announcement of it. Secondly, Once the order has been determined (which is usually a month before the end of the playoffs) the rest of the draft order is based upon the won-loss record of the teams in the playoffs, with the exception of the final 2 picks in the draft, which are reserved for the runner up and eventual NBA champion.
Big difference in signing a player arbitrarily in the middle of a season, because those players are free agents who have no contractual obligation to a team. Chances of actually finding a really good player through this method in the middle of a season are slim, for if they were deemed good enough, they would have already latched on to a team to begin with. Stranger things have happened.
I attached a video of this year's draft lottery so that you can get a better idea of how it works.
Please be advised that at the time of this airing, when then #6 pick came around, I was sweating bullets (long story, having to do with the Steve Nash trade from a couple of years ago), and when the first of the top two picks were announced, I was screaming like an 8 year old at a One Direction concert.