  In this letter, we note that the observed in the LIGO / Virgo experiment
ratio of the detection rate of black holes to the rate of detection of binary
neutron stars requires the assumption of a "conservative" collapse of massive
stars into a black hole: almost all the mass of the collapsing star goes under
the horizon. This is consistent with the large masses of black holes detected
by LIGO/Virgo. On the other hand, the assumption of a small loss of matter
during the collapse into a black hole is in good agreement with the small
eccentricity of Single-lined Binaries. At the same time, the absence of X-rays
from most black holes in binary systems with blue stars is explained. We argue
that three sets of LIGO / Virgo observations and data on the Single-lined
Binary with a Candidate Black Hole Component confirm the scenario of the
evolution of massive field binaries.
