  By relating fine and hyperfine spittings for l=1 states in bottomium we can
factor out the less tractable part of the perturbative and nonperturbative
effects. Reliable predictions for one of the fine splittings and the hyperfine
splitting can then be made calculating in terms of the remaining fine
splitting, which is then taken from experiment; perturbative and
nonperturbative corrections to these relations are under full control. The
method (which produces reasonable results even for the $c{\bar c}$ system)
predicts a value of 1.5 MeV for the $(s=1)-(s=0)$ splitting in $b{\bar b}$,
opposite in sign to that in $c{\bar c}$. For this result the contribution of
the gluon condensate $<\alpha_s G^2>$ is essential, as any model (in particular
potential models) which neglects this would give a negative $b{\bar b}$
hyperfine splitting.
