Soviet Union football league system
The Soviet Union football league system was a series of interconnected leagues for men's association football clubs in the Soviet Union which included "teams of masters" (a term for a professional association football team) from constituent union republics. The system has a hierarchical format with promotion and relegation between leagues at different levels, allowing even the smallest club the theoretical possibility of ultimately rising to the very top of the system. For most of its time, the all-union level had two tiers, while for a good portion of the Soviet period there existed  a third tier, and for a much less period, a fourth. The exact number of Soviet teams of masters varied from year to year as clubs (teams) joined and left leagues, folded or merged altogether. On occasions a season competition format included multiple stages with several groups including the top tier. The third tier (better known as the Second League) since its revival in 1963 consisted from about five to nine groups known as zones, the winners of which qualified to a promotional play-off tournament. Rotation between republican competitions and the all-union football "pyramid" existed only for the  Russian SFSR and the Ukrainian SSR. The Soviet Union football league system was dominated by teams of masters from the Russian SFSR and particularly from Moscow. The focal game of the top league initially involved the Moscow derby between Spartak and Dinamo (see Oldest Russian derby). Following World War II, there appeared winning CDKA (today known as CSKA), which was also known as the team of lieutenants. Following some reforms in the organization of competitions in the early 1960s, the top league champion's title was gained by clubs outside of Moscow as the Soviet Union football league system was  expanded with more teams of masters from various union republics and their regions (provinces). By 1980 the main game of the Soviet Top League became a rivalry between Russian and Ukrainian capitals Spartak Moscow and Dinamo Kiev (Dynamo Kyiv) (see Spartak Moscow–Dynamo Kyiv rivalry). The pyramid for women's football in the Soviet Union existed only in 1990 and 1991 (during the process of dissolution of the Soviet Union) ran separately to three tiers. 1936-1941. Initially, for the Spring championship of 1936 there were only seven teams participating in the top group, while for the Fall championship the  number of participants was increased to eight. A similar scenario took place in the second group as the spring championship saw some withdrawals. In the third group the number of participants was unchanged at eight for both parts of the 1936 season. At same time in the fourth group initially there were five teams for the spring half and six for the autumn. In 1937 the number of participants continue to grow. Some reshuffling took place between groups A and B, although initially both consisted of eight teams. Groups V and G increased their team pools to 10 and 12  participants, respectively. Also for the 1937 there was introduced the Group D with two subgroups. In 1938 all of groups were merged into one big super league of 26 teams. In 1939 and 1940 season Group A consisted of 14 teams. There also was a revival of Group B with 23 teams at first and then reduced to 14 as well. In 1941 season there was only Group A championship which was heavily adjusted to 15 teams.