Velocity-based planning is based on the premise that the amount of work a team will do in an upcoming Sprint is roughly equal to what they have done in prior Sprints. [3] Various assumptions are made such as a constant team size, similar type of work, consistent Sprint lengths, etc.
To utilise velocity-based planning the team needs to have base line data to form assumptions around the anticipated future velocity of the team. Hence, Story Point estimation plays a greater role.