So the themes of why certain states were able to colonize outside of Europe boil down to state centralization, and location. Russia was not at all centralized and still retained a feudal system where most of western Europe had already been transitioning away from by the 1500s. Countries like Spain and England had centralized to a point of having a clearly defined central government who could efficiently raise revenue (taxes) for purposes of exploring. They also are located right along the Atlantic with easy access to the sea. Russia did not have year round ice free port access and could not devote as many resources to building a infrastructure of exploring. What they did have were hundreds of thousands of acres to their east with no real challengers to its possession and seemingly internally colonized. They did have their possessions in Alaska and Even California but could not maintain California and of course sold Alaska to the Americans because it was some quick cash for frozen nothingness which they already had plenty of in Siberia. Africa and Asia came down to who industrialized first. England being the birthplace of the Industrial Revolution gained a significant chunk of Asia and Africa followed by France and other European states like Portugal and Holland taking possessions as well. Russia wasnt really industrialized until after WWI and had neither the resources to challenge for territories or hold them. They got their butts kicked by the newly industrialized Japanese in the Ruso Japanese war after Japan was starting to colonize Manchuria and Russia wanted to do it also. So in a 1 on 1 challenge against Japan who less that 40 years prior were still a backwater nation, the Russians lost. Think what would would happen if they went up against a more powerful and closer enemy. Oh, yeah...