An autonomous BOP system is provided for stopping an uncontrolled flow of formation hydrocarbons comprising two or more sensors distributed along a length of a subsea blowout preventer to monitor a drill pipe inside a blowout preventer and measure critical parameters. A subsea computer using predictive-software monitors a blowout preventer along with material critical parameters and calculates a blowout preventer configuration and sequence to arrest a well blowout. Blowout preventer components are fine-tuned and operational modes are added to aid an arrest of a well blowout under realistic conditions.