There was basically 4 versions of Tyson.The young Cus De Amato/Keven Rooney trained Tyson,The Tyson after De amato died and Rooney stopped training him,the post prison Tyson and the post Holyfied Tyson.
The young Cus De Amato/Keven Rooney trained Tyson was an undefeated beast,probably would have beat any fighter in history imo.
The Tyson after De amato died and Rooney stopped training him was good but lazy,no discipline,partying,celebrity lifestyle,not training etc.Thats the Tyson that lost to Douglas.
The post prison Tyson was after he spent years in jail and than returned to the ring.He was still good,still had knockout power, but stopped boxing and trying to set up the knockout and just swung for knockouts with haymaker left hooks and right crosses.If his opponents defense was bad and they couldn't take a punch he could still beat them.
After the Holyfield fights he was suspended and came back as pure shit.Thats the version Lennox Lewis fought.Lennox at that time was still near his prime.