The Hook Grip

This grip method used by Weightlifters and powerlifters. They use it for lifts such as the snatch, clean, and deadlift.
It is When you wrap your thumb around the barbell first. Then your fingers go around your thumb.
This grip creates a lock on the barbell. So that there isn’t a direction the bar can roll out of your hand, similar to a mixed grip (overhand and underhand).
Not only will it build a more symmetrical grip strength from side to side but it will also have a better skill transfer to your Olympic lifts if you were to use it in your deadlifts.
With a more secure grip on the bar using a hook grip. This will allow your upper arms to stay more relaxed and the force generated from your legs will better transfer to the barbell.

Although it’s very uncomfortable at first. The hook grip can be a very beneficial tool to have in your “gym bag”.