Ask ten different people who they think is the greatest quarterback of all time and you will likely get ten different answers. Some might say Tom Brady, others might say Johnny Unitas. Ask those same ten people what defines greatness in a quarterback and you may get another ten answers. Some may say it's the statistics, the touchdown passes, the yards thrown. Some may say it's the number of MVP awards. Others will likely say the only thing that matters is the Super Bowl victories, the only thing that matters is the rings. Quarterback may be one of the hardest positions in professional sports. There are so many skills one must possess and perfect. A great quarterback must have an outstanding arm. But it's not just the power to throw far, it's the combination of strength and pinpoint accuracy required to drop a pass over a receivers shoulder, into his outstretched hands, as he's running full speed downfield. A great quarterback must be dedicated and diligent, must spend hours studying film, studying the opponents tendencies, memorizing the play book from cover to cover. A truly great quarterback must have a laser like focus, to be able to analyze a play, to make a calculated decision in a nanosecond with several 300 pound behemoths bearing down on him. Many outstanding quarterbacks have played the game over the years, possessing all of these skills, yet it takes something extra special to be considered one of the greatest of all time. The following ten players have taken the position to another level, going above and beyond the competition.