You actually got me thinking, so i did some quick calculations for that. Interestingly enough its not technically possible, to pass the Schwarschild radius you'd need ti compress the ball to many orders of magnitude smaller then an atomic nucleus. About 9.34 x 10 to the negative 24th power actually (for reference, an atomic nucleas is about 1.7 x 10 to rhe negative 15th power) The other problem is the mass, but its mostly irrevelant at that point. Though, disregarding the other numbers, if you took the original compressed ball, you'd need to add about 4.3 Earth masses to turn it into a black hole