http://www.baseballprospectus.com/ar...rticleid=24223
Under the new Collective Bargaining Agreement, only draft picks in the first three rounds are “protected,” such that a team failing to sign the player receives a compensation pick in the following draft year. Because the Astros elected to use a non-protected, relatively early round pick on Nix, we can safely assume that selection was made with a high level of confidence that a deal could be reached.