Science Homework Help

Which cycle has the biggest impact on solar insolation, eccentricity, obliquity or precession？ 

Wikipedia says that — e sin(ϖ) is the precession index, which together with obliquity, controls the seasonal cycle of insolation. 
So think either obliquity or precession influence it biggest. I am thinking maybe precession plays a larger role? But I am not sure, could anyone correct me or explain a little bit?