AbstractAfter a definition of the bases of statistical computations allowing the description of the cis and trans stereoisomers distribution along the 1,4‐polybutadiene chains, the relationships between the distribution statistics and the mechanism of propagation are deduced. The parameters necessary and sufficient to describe the stereoisomer proportions and distribution are also established, as well as the parameters related to the determination of the most probable propagation mechanism. Analysis of typical samples are proposed to illustrate the method. Finally, a way is settled for computing the mean length of stereosequences.