  We investigate the misalignment of the circumbinary disk around the binary HD
98800 BaBb with eccentricity $e\simeq 0.8$. \cite{Kennedy2019} observed the
disk to be either at an inclination of $48^{\circ}$ or polar aligned to the
binary orbital plane. Their simulations showed that alignment from $48^\circ$
to a polar configuration can take place on a shorter timescale than the age of
this system. We perform hydrodynamical numerical simulations in order to
estimate the cavity size carved by the eccentric binary for different disk
inclinations as an independent check of polar alignment. Resonance theory
suggests that torques on the inner parts of a polar disk around such a highly
eccentric binary are much weaker than in the coplanar case, indicating a
significantly smaller central cavity than in the coplanar case. We show that
the inferred inner radius (from carbon monoxide measurements) of the accretion
disk around BaBb can exclude the possibility of it being mildly inclined with
respect to the binary orbital plane and therefore confirm the polar
configuration. This study constitutes an important diagnostic for misaligned
circumbinary disks, since it potentially allows us to infer the disk
inclination from observed gas disk inner radii.
