Grappler (Revised)

You’ve developed the skills necessary to hold your own in close-quarters grappling. You gain the following benefits:

• You have advantage on attack rolls against a creature you are grappling.
• You can use your action to try to choke a creature grappled by you. To do so, make another grapple check. If you succeed, you and the creature are both restrained until the grapple ends, but the grapple ends if you fail.  The target becomes unconscious if you maintain this choke for a number round equal to it's Constitution modifier, or it's Constitution score divided by 5.  It remains unconscious for a number of rounds equal to half your Strength modifier.  If the target is a spellcaster, it cannot use spells that have a verbal component.