To what extent were the mistakes of Stalin's opponents the main reason why he became leader?

Few would doubt Stalin was a strong and effective politician and that that this led to his leadership. How much of this power was due to the mistakes of those who surrounded him rather than Stalin's own ability or luck or the circumstances and structure of power? After Lenin died a collective leadership was introduced: the politburo. At this time Stalin was described as a gray blur opposed to people like Trotsky a charismatic and …showed first 75 words of 983 total…

…showed last 75 words of 983 total…and politicians of which Stalin was a good example and controller. Stalin's opponent's mistakes were very important in Stalin's rise and are intertwined with Stalin's political ability so far that they are of equal value. The nature of the party organization led Stalin to be the most suitable successor to Lenin as all Stalin did in the end was use the structures set up by Lenin to control the party and beyond that the USSR.