The one thing that makes sport great is rivalries. Baseball has series like the subway series. Football has divisional games which inferior teams can rise up and beat some of the best teams just because of the familiarity. I have been to an English Football derby and the electricity in the stadium is fantastic! Everyone - even the players - can understand the necessity of having someone against whom you compete. Someone who drives you to play better.
Golf has had its share of great rivalries. Consider Ben Hogan and Byron Nelson. These two guys grew up in the same caddie yard and then went on to compete on the PGA Tour. Hollywood couldn't have scripted a better story. There was the big three for a while with Jack Nicklaus, Arnold Palmer, and Gary Player. They were the foundation for the modern golf rivalry. Each golfer to a man says they were constantly watching what the other guys were doing. As Arnold began to fade with age, Tom Watson became a worthy competitor to Jack and provided one of the best mano e mano fights that golf has ever seen in The Duel in the Sun. Jack Nicklaus has always stated that Tom made him a better competitor. Jack won more but Tom would rise up and challenge Jack, and very often beat him.