How about the Game Master has the forum/arena set up in such away that they can manipulate the position of the tribute, for example aiming fireballs at a participant so they will move in a direction they want them to. Changing rules to the point it is a good idea to ally with a certain someone. TPTB were manipulating the situation, the tribute just had to take advantage of it. The GameMaster is like a producer/editor of any reality tv show and creates characters and tries to create story lines to interest the audience. Even Peeta jumped on the star crossed lovers story arc to create sympathy and perhaps get sponsors to help them.