  Higher moments of net-proton Binder ratio, which is suggested to be a good
experimental measurement to locate the QCD critical point, is measured in
relativistic heavy ion collisions. We firstly estimate the effect of
statistical fluctuations of the third and forth order Binder ratios. Then the
dynamical Binder ratio is proposed and investigated in both transport and
statistical models. The energy dependence of dynamical Binder ratios with
different system sizes at RHIC beam scan energies are presented and discussed.
