Half-kneel and reach to open one hamstring at a time.
Hinge from the hips with a tall chest, don't round your back to reach.
The half-kneeling setup fixes your pelvis in place, so when you hinge over the straight front leg, the stretch lands squarely on that hamstring instead of being stolen by a rounding spine. Working one leg at a time lets you park extra time on the tighter side. It earns its place after leg days and hinge sessions, and as prep work when Romanian deadlifts or toe touches feel blocked.
You are probably rounding your back to reach your foot, which slackens the hamstring. Keep the chest tall, hinge from the hips, and stop reaching with your hands, tilting the pelvis forward is what loads the stretch.
Yes, heel down and toes pulled up lengthens the whole back of the leg and adds a light calf stretch. Letting the foot flop relaxes part of the chain and softens the stretch.
Little and often beats one long weekly session, 30 to 45 seconds per side most days moves the needle. Pair it after training when the muscles are warm and the stretch will feel noticeably deeper.
