Rous simplified the laws of the game and was the first to use the diagonal system of control.
Although old fashioned and a bit of a racist (probably no more so than most white Englishmen in those days) in most books Rous is the good guy compared to his successor Joao Havelange. Where Rous was against professionalism and refused to be paid for his work (he even didn't want a pension), Havelange made getting rich and powerful from being the boss into an art. The Brazilian also did not receive a salary, but he was very creative with his bills and bribes.
Rous was ousted by Havelange after the Brazilian had been travelling extensively in, mostly, Africa, visiting local FAs making promises. Rous never really lobbied for his job, thought he would be elected anyway. To be able to travel and lobby Havelange used money from the Brazilian FA.
From our reporter: James Ng