Establishing good grips in BJJ and Judo is so important as very often when you dominate the grip battle and establish your dominant grips you can control and dominate your opponent. I personally work my grips by climbing rope and doing pull ups with my gi. I also rock climb whenever I have the time. Many top BJJ players use rope climbing as a staple of their daily training. Fernando Margarida was said to have spent at least an hour per day on his rope training.
Pull ups are also one of the best ways to build upper body strength.
In a sport like Jiu-Jitsu were you are constantly pulling, grabbing and holding your opponent having grip strength and endurance is very important.
Stephan Kesting from http://www.grapplearts.com demonstrates 19 pull-up variations he uses in conditioning for BJJ and submission wrestling.
You need more than just technique, you need GAME CHANGING concepts & details.
Calling this instructional “Game Changer” is possibly the understatement of the millennium. This must be the greatest collection of BJJ concepts, theories, and applications EVERY filmed. Paul Schreiner (main instructor at Marcelo Garcia Academy NYC) breaks down the “how’s” and “why’s” & goes into great detail about mechanics, movements, positioning and more. The depth of the material covered in this series is so deep this may be the one instructional you will refer to throughout your BJJ journey.