  The article considers a way to compare large bulks of experimental data with
theoretical calculations, in which the quality of theoretical models is clearly
demonstrated graphically. The main idea of the method consists in grouping
physical observables, represented by experiment and theoretical calculation,
into samples, each of which characterizes a certain physical process. A further
choice of a convenient criterion for comparing measurements and calculations,
its calculation and averaging within each sample and then over all samples,
makes it possible to choose the best theoretical model in the entire
measurement area. Published theoretical data of the three-fluid dynamic model
(3FD) applied to the experimental data from heavy-ion collisions at the energy
range $\sqrt{s_{NN}}\,=\,2.7 - 63$ GeV are used as example of application of
the developed methodology. When analyzing the results, the quantum nature of
the fireball, created at heavy ion collisions, was taken into account. Thus,
even at energy $\sqrt{s_{NN}}\,=\,63$ GeV of central collisions of heavy ions,
there is a nonzero probability of fireball formation without ignition of the
quark-gluon plasma (QGP). At the same time, QGP ignition at central collision
energies above at least $\sqrt{s_{NN}}\,=\,12 GeV occurs through two competing
processes, through a first-order phase transition and through a smooth
crossover. That is, in nature, these two possibilities are realized, which
occur with approximately the same probabilities.
