The main difference between non-black hole forming and black hole forming star is initial mass. Stars below a set mass will never supernova and will never become a black hole. Even stars that supernova aren't guaranteed to form a black hole; if the central mass left over isn't beyond a given mass(~2.2- 2.9 solar masses)*, a Neutron star will be the result instead. * this is the remaining mass, since the majority of the star's mass is blown off in the supernova, the initial star mass needs to be many times this. Given that a typical stellar black hole masses between 3-10 solar masses, it means only stars much, much more massive than our sun ever have the chance of forming a black hole.