The need for a rivalry to be so intense that highlighting their differences is the first thing that comes to mind. However, it might also be helpful to look into areas of similarity between the two rivals.
Think about Monica Seles and Stefanie Graf. Everybody was introduced to tennis by a driven father. Everybody had a great work ethic and gave their practice hours of undivided attention. Each centered their playing strategies on strong, baseline-based power, which transformed the game of women’s tennis. Graf and Seles hardly ever gave up baseline territory. Of course, each was also a fierce rival. Together, the two would win 160 WTA singles titles, including 31 Grand Slams, and remain at the top of the rankings for 555 weeks.