It's interesting to watch MMA guys and wrestlers like Jon Fitch and Jake Shields that have been black belts for a while. It seems like they mostly pass from the knees, and it definitely makes it harder for someone like Rafa that plays a modern RDLR/DLR open guard style to play their go-to offense. Rafa was a little more limited, and I think it may have been a bit more exciting if Jake had a style that involved passing standing or with one knee up. Andre Galvao jokingly says that Rafa and Keenan have "boring" nogi guards that are basically un-passable but it's true. The way Jake Shields was trying to pass would never break through the "RDLR shield". Also looked like Jake Shields looked really tired before the roll even started.
Marcelo obviously is super aggressive from the seated/butterfly guard, and was all over Jake when they rolled. It's cool to see the differences between two badass dudes like Rafa and Marcelo and how they approach playing the guard. I like seeing Jake Shields doing straight grappling, and after his match with Lo I think he could medal at some major tournaments with the right training camp.