  Light curves of the contact systems visible in the direction of Baade's
Window have been analyzed using the first coefficients of the Fourier
representation. The results confirm that the geometric contact between
components is usually weak. Systems showing significant differences in the
depths of eclipses are very rare in the volume-limited sample to 3 kpc: only 2
among 98 contact systems show the difference larger than 0.065 mag; for most
systems the difference is <0.04 mag. If this relative frequency of 1/50 is
representative, then one among 12,500 - 15,000 Main Sequence F-K spectral-type
stars is either a semi-detached or poor-thermal-contact system. Below the
orbital period of 0.37 day, no systems with appreciable differences in the
eclipse depths have been discovered. Since large depth differences are expected
to be associated with the "broken-contact" phase of the Thermal Relaxation
Oscillations, this phase must be very short for orbital periods above 0.37 day
and possibly entirely absent for shorter periods. In the full sample, which is
dominated by intrinsically bright, distant, long-period systems, larger
eclipse-depth differences are more common with about 9% of binaries showing
this effect. Sizes of these differences correlate with the sense of light-curve
asymmetries (differing heights of maxima) for systems with orbital periods
longer than 0.4 day suggesting an admixture of semi-detached systems with
accretion hot spots on cooler components. The light-curve amplitudes in the
full sample as well as in its volume-limited sub-sample are surprisingly small
and strongly suggest a mass-ratio distribution steeply rising toward more
dissimilar components. Many low mass-ratio systems remain to be discovered in
the sky field.
