A signability pick is a player who is likely to sign a professional contract quickly and for what is viewed by the team selecting him as a reasonable amount of money given his slot in the amateur draft. Often these players receive a signing bonus less than that received by the same pick the year before or the year after. Also, these players may be viewed as not deserving this slot in the draft based solely on their baseball talents. The opposite can also be observed if a player falls to a rank well below his talent because teams are concerned about his "signability", i.e. the amount of money that would be required to convince him to drop a commitment to go to college or return there for another year.
While the practice was prevalent in the 1990s and 2000s, it was very unpopular with fans, and Major League Baseball took steps to prevent it. The amateur draft comes with a target signing bonus assigned to each slot, which teams are not allowed to exceed lest they face significant penalties; teams are also allotted a signing bonus pool which cannot be exceeded. As a result, it is much more difficult for drafted players (or more precisely their agents) to hold teams for monetary ransom. In addition, front offices have figured out that in spite of the steep cost of a signing bonus, it is still worthwhile in the long run to invest in a top talent, instead of wasting a valuable top pick on a signable player who has little or no chance of becoming a star.
Agent Scott Boras has never represented a player viewed as a signability pick.