In BJJ, most experienced practitioners are used to defending front triangles. These are the type of triangles set up from a guard position, either closed, half, or open guard.
You can usually set up the front traingle from a spider guard or from a lasso guard etc.
The back triangle is another common triangle set up used in Brazilian jiu-jitsu especially in the past few years. This is usually applied when you have your opponent’s back and trap an arm and then lift the other arm, falling to the side to trap a triangle. This triangle is very difficult to get out of.
A few years ago, Braulio Estima shocked the world When he was able to submit many world-class opponents at ADCC 2009 with a reverse triangle set up from an open guard. Victims of this reverse triangle included Andre Galvao and Xande Ribeiro.
There is another triangle variation which is much less common in BJJ. It is usually set up when the opponent is turtled. The turtle position is not as common in BJJ as in judo. One effective way to get your opponent to turtle is to threaten them with a guard pass. Usually if they have a very good guard which is difficult to pass, you can attempt a guard pass which will force him to defend by turtling up. When this happens, you have the perfect situation to set up a very dangerous reverse triangle.
This reverse triangle setup was seen at Bellator MMA hey a few years back when Toby Armada was able to put Jorge Masvidal to sleep with it.
Ryan Hall has some great pointers on how to add more breaking power to the Kimura from the reverse triangle. Most people get it wrong and can’t finish their opponent.
It’s important to rest your bottom under the opponent’s leg, NOT under the shoulder.