  Our understanding of the convective-engine paradigm driving core-collapse
supernovae has been used for 2 decades to predict the remnant mass distribution
from stellar collapse. These predictions improve as our understanding of this
engine increases. In this paper, we review our current understanding of
convection (in particular, the growth rate of convection) in stellar collapse
and study its effect on the remnant mass distribution. We show how the depth of
the mass gap between neutron stars and black holes can help probe this
convective growth. We include a study of the effects of stochasticity in both
the stellar structure and the convective seeds caused by stellar burning. We
study the role of rotation and its effect on the pair-instability mass gap.
Under the paradigm limiting stellar rotation to those stars in tight binaries,
we determine the effect of rotation on the remnant mass distribution.
