When my student's head lock does work on their opponent, I would tell them that:
- They need to bend their opponent's spine side way (not forward).
- When they lock on their opponent's head, their locking arm elbow should point straight down to the ground.
- They need to put their opponent's head on their chest.
- They need to control their opponent's leading arm.
- They need to use hay-maker to knock on the back of their opponent's head and knock them out half way.
- ...
If all these requirement has be met and if their head lock still don't work, they will need to spend more time to hang on the pole.