Wikipedia
Bald–hairy
Bald–hairy is a common joke in Russian political discourse, referring to the empirical rule of the state leaders' succession defined as a change of a bald leader with a hairy one and vice versa. This consistent pattern can be traced back until as early as 1825, when Nicholas I succeeded his late brother Alexander as the Russian Emperor. Nicholas I's son Alexander II formed the first "bald–hairy" pair of the sequence with his father.
The current "bald–hairy" pair of Russian rulers are the balding Vladimir Putin and the hairy Dmitry Medvedev (who has a full head of hair). Putin was the president from 2000 until 2008, Medvedev held the post until 2012, and Putin became president again in 2012.