*
1890-1920 timeframe? Here goes but its pretty ASB.
*Japan manages to not only destroy the Russian Pacific fleet but also manages to inflict disproportionately high losses on the Russian army as well. Britain offers stronger backing to Japan hoping to stick the knife further into Russia in the peace deal due to a more deadly clash in the North sea with the Royal Navy. Thus, Teddy Roosevelt fails to limit Japan's demands resulting in it gaining all of Karafuto, Kuril and heavy indemnities. Britain also backs Japanese interests in Manchuria but not into China proper which further humiliates Russia,
*Tsar Nicholas II refuses to sign October Manifesto in 1905, arguing much longer on the point than OTL, peasant and civil workers revolt much more violently. Cities are seized by the rebels since the Tsar lacks the initial military power to put down the rebellion everywhere quickly. Eventually, the military does rally and we end up with a massacre and long standing simmering hatred of Nicholas and his family,
*1908-Tunguska incident occurs over Moscow, wiping the city off the map and further crippling the Russian economy.
*1909-Military step in and the Tsar and his family are placed under house arrests following mass protests over the economy and general continued unpopularity of Tsar Nicholas II.
*1910-Military clique evolves into a greedy kleptocracy so bad that some wish for the Tsar's return. A botched rescue by lingering supporters leads to death of the entirety of the Tsar's family. The event captures international headlines and condemnation from other powers leading to increasing diplomatic isolation.
*1911-Famine cripples the country due to bad harvests and inefficient distribution systems. Military modernisation is much reduced due to massive corruption.
*1914-Russia is on the cusp of civil war with various classes and ethnic groups finding the government increasingly intolerable. July incident still occurs and the Russian regime still mobilises against Austria-Hungary leading to a declaration of war from Germany and Austria-Hungary.
*1914-1916-war is a catastrophe for the Russian army which has been hollowed out by years of neglect and a failure to invest in new equipment and logistical support. Huge casualties suffered against Austria-Hungary alone, mass desertions occur and various ethnic groups take the opportunity to declare independence leading to rapid CP in-roads into Poland, Ukraine and the Baltic states.
*1916-government collapses and Russia lapses into full blown civil war between separatists, communists and militarists along with any number of minor factions.
* 1918-the earlier bowing out of Russia results in a CP victory. The civil war concludes with a hyper religious/ quasi fascist dictatorship (led by Rasputin) in charge wanting to return Russia to its perfect state-a rural agrarian society. They sign a peace deal with Germany losing all the Baltic states, Poland, Ukraine, Caucasus and much of Belorussia. Japan opportunistically annexes everything in E. Siberia. The Russian dictatorship begins to systematically destroy the Urban infrastructure of the state and moves people to the countryside to work on communal farms ( think Pol-Pot but worse and longer).
*1920-Russia is a failed, horrible 3rd world state with a dictatorship rapidly killing off its own population through famine, forced labour and deliberate murderous desire.