What I call the Underdog Pass is a very common way to pass the guard in BJJ. This pass is done when you get double underhooks under your opponent's legs to pass. Because it's a solid way to pass I came up with a position that I call The Right Angle to deal with it.
In the video below Braulio Estima demonstrates another way to deal with the Underdog that fits right in with the Right Angle. Instead of trapping his opponent at the double underhooks, Braulio is kicking his leg past his opponent's arm so he has one arm in and one arm out and then finishing the tekk with a straight arm lock ( which he gives some great details in by the way ). There is also a Triangle right there for the taking !
