A skilled grappler may employ this position effectively depending on the situation. However, standing headlocks are commonly used by those who lack grappling skills. This is often not only ineffective, but dangerous as this video demonstrates.
These cops first attempt to control the man by grabbing the wrists, just as they have been trained to do. The suspect passively resists, denying control. The cop then moves to the schoolyard headlock which is similarly effective. OC spray is then used which also apparently does not work. A second man begins to intervene. Video ends with no resolution.
The first officer to make physical contact attempts an armbar takedown which serves to spin the man around while remaining on his feet. Other police swarm and start grabbing at his arms and wrists. The police pull the man in all directions at the same time, which prevents escape but does not help to take him down.
One officer makes a half-hearted attempt at controlling the legs, but lets go. The man eventually is forced to lean forward, and in combination with tripping over the feet of one officer while being pulled forward in a headlock by another, he falls to the ground.
Police make the mistake of attempting to handcuff before gaining control of this suspect. As they pin him against a wall while standing, they start grabbing for wrist locks and/or arm control while releasing any kind of control of the man’s body and posture they had gained. He twists and strips his arms free, then knocks out the male police officer with a punch.