A companion paper examines hailstone sizes using dual-pol radar observations (Kumjian and Lebo; this conference). In the present work, we examine the environmental conditions most suitable for the formation of large versus small hail in supercell storms using high-resolution numerical simulations with a state-of-the-art bin microphysics scheme, which is better suited to represent microphysical processes that are highly dependent on the ambient hydrometeor size distributions than traditional bulk modeling frameworks. The work builds off of a recently submitted paper in which the magnitude of the deep layer east-west shear was found to play a key role in elongating and enlarging the hail growth region, resulting in large hail mass mixing ratios. We further explore this problem by examining the shear-CAPE parameter space using size-resolved (i.e., bin) microphysics, permitting a more comprehensive analysis of environmental factors and an improved representation of hail sizes. We elucidate the portion of the parameter space that is deemed most critical for the formation of large destructive hail versus that of small accumulating hail, which can aid in forecast lead times in the event of severe weather.