Is the number of light flavors in QCD great?

At a qualitative level, it is well known that QCD featuring a large number of quark flavors must differ drastically from actual QCD. However, it is possible to consider the large-Nf limit (where Nf is the number of light flavors in QCD) such that the basic dynamics of the system remains unchanged. This is the region of chiral perturbation theory, where the limit Nf → ∞ is simultaneously the limit of a large number of colors, Nc. Features are indicated that make it possible, in such a situation, to compare analytically the same quantity in a simplified model of actual QCD and in the large-Nf limit, and methods are proposed for calculating these features. Calculations in the limit Nf → ∞ are of no use in assessing quantities of the theory at small N f.