Kevin Ferguson of KFAN 1320 in Salt Lake City asked via Twitter how scouting combine officials decide which college players to invite each year.
The official combine site explains it this way: "Participants are determined annually by a Selection Committee. The Directors of both National and BLESTO scouting services, which combined represent twenty-five NFL teams, are joined by members of various NFL player personnel departments to form the committee. The participating NFL executives can rotate on a yearly basis, and remain anonymous. ALL eligible players are reviewed and voted on by the committee members. Each athlete receiving the necessary number of votes, by position, is then extended an invitation. While it is not a perfect science, the goal of the committee is to invite every player that will be drafted in the ensuing NFL Draft."
The site also provides a position-by-position schedule showing when players from the various position groups register, undergo pre-exams and X-rays, submit to orientation, grant interviews to teams and reporters, undergo psychological testing, work out and meet with the NFLPA.