This paper studies the general relationship between the total deficient value of the meromorphic function and the total number of Borel directions to guide evolutionary calculations. The total deficient value of the meromorphic function is one of the main contents of the argument distribution theory, and the total number of Borel directions is the first in the complex analysis. The basic evaluation theorem of the class, the complex value in its definition is extended to the case of small functions, and the definition of the deficient function is obtained. At the same time, the definition of the Borel direction under the deficient function as a rational function is obtained. From these new definitions, we prove For the meromorphic function ????(????) that satisfies the growth condition lim?????? ????(????,????) ln2 ???? = ? in the entire complex plane, there is at least one Nevanlinna direction whose loss function is a rational function.