  We compare glassy dynamics in two liquids that differ in the form of their
interaction potentials. Both systems have the same repulsive interactions but
one has also an attractive part in the potential. These two systems exhibit
very different dynamics despite having nearly identical pair correlation
functions. We demonstrate that a properly weighted integral of the pair
correlation function, which amplifies the subtle differences between the two
systems, correctly captures their dynamical differences. The weights are
obtained from a standard machine learning algorithm.
