We've all heard the news about the detection by gravitational waves of two black holes, one 29 solar masses and the other 36 solar masses, spiraling into each other to create a single black hole of 62 solar masses.
For me, the loss of three solar masses into the gravitational waves over a fraction of a second is the most amazing aspect of this. I can understand how the waves were created (and mass changed into broadcast energy) by the spiraling motion of the black holes as they did their final do-si-do, and it's clear that losing that energy was a necessary part of their joining; otherwise they would have orbited forever.
However, does the amount of mass lost depend on just how the two holes merged? For instance, if they had rammed each other head-on, would they still have somehow lost that amount of energy? I expect that less energy would have been diverted into the resultant black hole's spinning, but I don't know how that would have changed the resulting mass.