  We demonstrate the importance of anisotropic neutrino radiation in the
mechanism of core-collapse supernova explosions. Through a new parameter study
with a fixed radiation field of neutrinos, we show that global anisotropy of
the neutrino radiation is the most effective mechanism of increasing the
explosion energy when the total neutrino luminosity is given. We discuss the
reason why, and demonstrate how sensitively the success of a supernova
explosion depends on the neutrino luminosity.
