This term is used in football to describe players on the team capable of making "big" plays. The use of this term is subjective and depends on the player and the speaker. In the game of football, a "big" play is used to move the ball a greater than average distance down the field. These plays may be for long touchdowns, or simply to get out of a difficult situation. The individual playmaker is the athlete capable of making this "big" play happen without the need to call a "big" play in the huddle. The playmaker will use their skill and athleticism to gain the big yardage.
Although a playmaker can be any player on the team capable of making big plays, this adjective is usually bestowed on the skills players on the team. On the offensive side, this includes the quarterback, receivers, running backs, and tight ends. On the defensive side, it could be any of the players on the field, though the term playmaker will most often apply to offensive players. In order to succeed and win lots of games, teams typically need a few playmakers on both offense and defense. An example of a playmaker is Hall-of-Famer Deion Sanders.