Ohhh, MMA, nice - Mr. Ice cold himself...hahaha...at 235 lbs, he's not small, that's for sure.
Most of his fights was bare knuckle fights no rules 3 or 4 fights in 1 night tournaments , he was unbeatable at one time 
Bare knuckles is brutal...I used to box when I was a teenager, and even wearing the headguard would rock my head. Apparently this guy is one of the hardest hitters in MMA history. Who was his toughtest fights, in your opinion?
Yes in my opinion he is also the most underrated fighter of all time, his losses came later on in his career when rules was applied time limits and gloves plus he was older and had injuries 
I didn't realize he won 37 fights in a row!
Ye his toughest fight was probably his first fight with a man named nick nutter it  was half hour long and both had fort 3 fights previously , igor won by a backwards headbutt 
Nick Nutter? What an awesome name for a fighter, lol.Cool that his last fight was in PRIDE, fighting in a 4 man tourney
pride was a MMA organisation in Japan that was bigger than the UFC it was the first major MMA organisation and it was in a ring with time limits and gloves  
I used to watch way more PRIDE growing up...I remember it being so brutal, loved it. I heard they had controversy though, like Fixed fights, fighters getting short notice to fight, and 'freak show" fights, lol...started turning into sensationalist fighting like professional wrestling at some point...
Yes and its strange the Japanese crowd was silent through out the fight only made a slight noise when the fighters was trading punches e.t.c
They should bring that back but regulate it more so it's not run by the Yakuza