okay, this may end up being a complete bust... but one of my favorite games to play about mma is to look back at where a fighter took a specific path or was dealt a certain hand that dictated the next several years of their career.
let's say that because of a random win or injury, they were either skyrocketed to the top of the world, or dropped damn near off the map. the best example is matt serra. he was in TUF because he had fallen into prelim obscurity, and won the tournament with a controversial split decision over chris lytle due mostly to foot stomps. because of that, he challenged the unbeatable champion, won by flash KO, became a UFC champion and raised his stock substantially, leading to a coaching gig on TUF and a rivalry with matt hughes. had he not won against lytle in the way that he did, none of what followed would have happened, and mostly likely, he would have continued to age on the undercard until being cut or retired.
3-4 years ago, when fedor became a free agent, and dana was courting him to come to the UFC for an automatic title shot against brock lesnar. for reasons simultaneously unknown and named vladimir, fedor never took the offer... which led to him joining strikeforce for a career-crippling run of losses, which, while they were to top-tier talent, still tainted his legacy because they didn't occur in the UFC octagon, and according to the widely accepted word according to dana, showed his inability to hang even in the b-leagues.
if fedor had signed to the UFC, i have little doubt that he would have blitzed lesnar within 3 minutes, in the 'biggest win' of his career. the next step is where it gets a bit harder. JDS was nearing the end of his 'contender streak', having just beaten roy nelson. the two biggest challengers to the belt at the time were carwin and velasquez. i see fedor beating carwin, but being overpowered by velasquez for losing by UD. i don't see him being the JDS of 2010 either. after losing the title, winning big money fights against couture, big nog, or mir would have driven him to another losing title shot against JDS.
anyone have one to offer? also, let's keep this to alternate history, without extending to revisionist history. do your best to keep the dates, records, and abilities at the time in reference.