  In Gayon & Bois (2008) and Gayon etal (2009), (i) we studied the theoretical
feasibility and efficiency of retrograde mean motion resonances (i.e. two
planets are both in orbital resonance and in counter-revolving configuration),
(ii) we showed that retrograde resonances can generate interesting mechanisms
of stability, and (iii) we obtained a dynamical fit involving a
counter-revolving configuration that is consistent with the observations of the
HD73526 planetary system. In the present paper, we present and analyze data
reductions assuming counter-revolving configurations for eight compact
multi-planetary systems detected through the radial velocity method. In each
case, we select the best fit leading to a dynamically stable solution. The
resulting data reductions obtained in rms and chi values for counter-revolving
configurations are of the same order, and sometimes slightly better, than for
prograde configurations. In the end, these fits tend to show that, over the
eight studied multi-planetary systems, six of them could be regulated by a
mechanism involving a counter-revolving configuration.
