What is a fundamental purpose of a blocker in roller derby?

The fundamental purpose of a blocker in roller derby is to defend against the opposing jammer. Blockers play a crucial role on the track by creating a barrier that prevents the opposing team's jammer from passing through. Their primary objectives include using their body to impede the jammer's progress, maintaining their own position on the track, and helping to maintain a cohesive defensive formation. This defensive strategy is vital in roller derby, as successfully blocking the opponent's jammer can help the team control the pace of the game and setup potential offensive plays by freeing their own jammer for scoring opportunities.

In contrast, the other choices highlight roles that are not the main focus for blockers. Scoring points is typically the responsibility of jammers, while calling plays is usually reserved for team captains or designated players who focus on strategy during gameplay. Assisting the jammer during a scoring pass is more aligned with the responsibilities of a jammer or pivot, rather than a blocker. While blockers may help create openings, their essential role is to act as defenders against the challenging jammer.