The purpose of the NFL Draft is to control talent.
If it was open season for teams and rookies, the most competitive and well-off franchises would attract all the best talent.
After seven rounds of the worst teams getting "dibs" on their favorite prospects and the best teams going last, parity is fostered, and the league stays balanced.
Somewhere around the sixth round, though, teams start targeting priority free agents. Calls are discreetly made between teams, agents and players to begin working on deals if the players fall through the end of the seventh round.
As LouisianaDaily.com reported, former LSU wideout Russell Shepard admitted to radio station WNXX that he "signed" with the Eagles while picks were still coming off the board. Why commit this huge no-no?
As Mike Florio of Pro Football Talk explained, Shepard believes he'll have the opportunity to contribute in several different ways in Philadelphia. Why wouldn't he go to a team who's enthusiastic to have him instead of a team who's just crossing the next name off its list?
Putting aside the "because it's against the rules" thing, this is exactly why undrafted free agents are so important: They may not have been one of the consensus best 250-or-so players, but when they get put on the team where they fit best, they can make a big impact.
Here are 20 of the most notable undrafted free agents, where they went, my grade of just how good of a fit their teams are and how likely they are to make an impact.