Historically the RSDRP decided, along with other radical left-wing parties, to boycott the First Duma. As a result the Duma was dominated by the Liberal Kadets and the moderate SR offshoot the Trudoviks.
This decision was not unanimous, however, and there were those within the party who called for the party to participate in the elections, albeit for very different reasons. The right-wing of the Menshevik faction, the Liquidators, wanted to move away from clandestine insurrectionist activity now that legal channels of political action were available (and I think they ultimately ran candidates), whilst the right-wing of the Bolsheviks under Lenin wanted to use the Duma as a bully pulpit to call for revolution.
If the Social Democrats decided to fully contest the elections, how many seats would they have been likely to win, how would the presence of a significantly more radical party* have affected the already quite hostile Duma, and what affect, if any, would this have on Russian politics in the near future?
* Remember this was back when Social Democrat was synonymous with revolutionary socialist