Stalin's position as General Secretary proved to be very important in his seize of power for many reasons. One reason for this is that it gave him the ability to control party membership which was extremely beneficial as it meant he could bring people that supported him into the party and also he could kick out those who did not agree with his ideology. Another reason is that it allowed him to undermine his rivals’ power bases meaning he could sway the opinions of others into supporting him over the other competitors in the running for power.
However, there were many other factors that contributed to Stalin's seize of power. One example of this is that the Bolsheviks made many errors, both general and individual.
An example of a general error is the underestimation of Stalin. This was beneficial as it allowed Stalin to make moves without anyone suspecting him of doing anything particularly damaging to their success. Another example is the failure to publish Lenin's testament. This was a mistake as the opinions Lenin voiced about Stalin's inabilities were the last real opportunity to stop Stalin.
There were also individual errors that all the contenders made that benefitted Stalin.
Trotsky made many errors in his attempt to seize power. One example of this is his failure to attend Lenin's funeral as it made him seem disrespectful to the previous leader, and allowed Stalin to give the speech. Another of Trotsky’s mistakes was leaving himself vulnerable to a factionalism charge after the 13th party congress, which was a negative as it left him unable to voice his opinion and