The evidence is mounting that a range of exercises are necessary, if athletes want to achieve complete hamstrings development. 

This new study shows that 4 different exercises produced very different responses in each of the 4 hamstrings muscles and 3 main regions (proximal, middle, and distal) when measured using MRI from pre- to post-exercise. 

This suggests that both hip extension exercises (e.g. Russian belt deadlift and hip extension conic pulley, as in this study) as well as knee flexion exercises (e.g. Nordic curl and flywheel leg curl, as in this study) are necessary to achieve increases in muscular strength and size of all hamstrings muscles and regions.