  The correlation between the magnetic moment in ferromagnetic alloys and the
tunneling spin polarization in ferromagnet-insulator-superconductor tunneling
experiments has been a mystery. The measured spin polarization for Fe, Co, Ni,
and various Ni alloys is positive and roughly proportional to their magnetic
moments, which can not be explained by considering the net density of states.
Using a tight-binding coherent potential approximation (CPA) model, we show
that while the polarization of the net density of states is not correlated with
the magnetic moment, the polarization of the density of states of {\it s}
electrons is correlated with the magnetic moment in the same manner as observed
by the tunneling experiments.
  We also discuss the spin polarization measurements by Andreev reflection
experiments, some of which obtained different results from the tunneling
experiments and our calculations.
