The Half Nelson and Claw Ride are very complimentary top techniques, as you can easily bounce back and forth between the two. They work well in controlling your opponent's upper body, but you must make sure to maintain a good tight waist to also control the hips.
This is one of the more preferred rides for a leg rider, because it allows for good control while leeching onto the opponent, pulling him into a crab ride, and looking to throw legs.
The half is also one of the easiest ways to pin an opponent because if done correctly you'll have complete control over his head and neck. Always go for a regular half. The reverse-half is too unstable and should only be used to stop a roll in progress. Then you tighten up your tight waist and go back to the regular half.
Do not let go of the tight waist. Another gripe about school program coaches, they teach to grab the near leg. This is unsatisfactory, it gives up your needed control on the opponent's hips. Against a good wrestler, you let go of the hips and go to grab his leg and by that time he has circled away and gotten free.
Your left hand will go under his left shoulder and then go across his neck. Try to grip as far across the neck as possible using your fingertips. Try to tilt your hand forward, forming your hand into a karate chop of sorts. This will apply the same amount of pressure, but over a smaller surface area, focusing the pressure and making it stronger.
Some coaches will teach to palm the head, do not do this. The older your opponents, the stronger their neck will be and the less likely that will work.