When looking at the downfall of many of the best fighters of past eras, I notice a common trend of fighters who habitually used a technical, or at least varied arsenal of both standup and grappling techniques who, over the years, abandoned much of the style that made them so successful, particularly in terms of defense, and started to just swing for the fences with the objective of finishing their opponents as quickly as possible, be it due to physical decay or plain complacency. The two prime examples of this are, in my opinion, Shogun and Fedor. An argument could be made that both fighters always had a highly aggressive style, but it's very egregious to me how Fedor abandoned most of his grappling after his Pride career and started to rely on his big right hand to do most of the job. Shogun also abandoned most of his kicking technique in recent years, stopped emplying effective movement and became extremely hittable and also hasn't shown almost any of the excellent jiu jitsu he did in his Pride career.
(Interestingly, Wanderlei Silva suffered an inverse process, as he became more tentative and less agressive as his chin started to give out).
