  We subject to an N-body numerical investigation our analysis of Paper I on
the survival of stellar clusters undergoing rapid mass loss. We compare
analytical tracks of bound mass-fraction {\it vs} star formation efficiency
$\epsilon$ to those obtained with N-body integration. We use these to argue
that stellar clusters must develop massive cores of high-binding energy if they
are to remain bound despite a star formation efficiency as low as 30% or lower
suggested by observations. The average local virial ratio $<\sigma^2/|\phi|>$
is introduced to classify bound clusters as function of their critical
$\epsilon$ for dissolution. Clusters dissolving at lower $\epsilon$ achieve the
lowest ratio. We applied this classification parameter successfully to
Michie-King and Hernquist-type distribution functions. The Plummer sphere is
exceptional in that it defies this and other classification parameters we
tried.
  The reasons for the discrepancy include less effective energy redistribution
during the expansion phase for this case.
