It kinda hand waves over a number of parts and is more simplified than what I was looking for. To give a very very simplified summary of my reading and the que

It kinda hand waves over a number of parts and is more simplified than what I was looking for. To give a very very simplified summary of my reading and the questions I have remaining, it seems to be there are two equations for what is going on here. One is the force of gravitational and light radiation collapse that results in the initial increase in heat and the other is for the force of oxygen explosion. At under 50 solar mass, the oxygen explosion is 0 and so it forms. At 50 to 65 solar mass, the oxygen explosion is enough to throw off mass but not enough to obliterate the star, which eventually moves it to the 50 solar mass range. At 65 to 130 solar mass, the oxygen explosion is violent enough to destroy the star without a black hole. At 130+ solar mass, the oxygen explosion is too weak to overcome the gravitational collapse force and a black hole forms (but masses this large seem to be rare). What I'm wondering is why are those the specific numbers. Is it really just a case of 'take the equations, plug in the numbers, and this is what you get', or is there some explanation that is easier to conceptualize. For example, the 50 cut off seems to be that is the threshold needed to even have oxygen ignite. But for 50 to 65, why isn't the explosion enough to destroy the star? At this point, the force from gravity holding the star together would be less than at 65+ solar mass, so why isn't the core obliterated? Is it because there is a different sort of oxygen explosion that only happens under the force of 65+ solar mass that is much stronger than the one that happens at 50 solar mass? And as for the 130 threshold, shouldn't the more solar mass mean the more oxygen to explode, so shouldn't the force of the explosion continue to be higher than the force of the gravitational collapse? The article clearly claims this isn't the case, but doesn't explain why. P.S. Now that I'm reading over it again, I think there might be three forces and I misunderstood the direction of the light radiation force that invalidates all of the above. It appears the light radiation is pushing outward, same direction as the oxygen explosion. If I consider all three forces it might be the model I'm looking for.