Submitted for user Aesopian!
The s-mount game gets another layer deep with this tutorial. We're entering the world of counters, re-counters and combos.
This tutorial could have been broken in two. The second half is how I finish all of my triangles from guard, but I thought I'd cover that too. So you should mentally apply this new knowledge to other triangle setups than the one shown below.
Let's get started.
I am going for the armbar from s-mount, which you should be familiar with by now.
But before I can pass my leg over for the armbar, Trog sharply turns into me and drives his elbow to the floor, bringing it lower than my hips. This is a common armbar escape. With his elbow out, I have no chance at recovering the armbar.
Once his elbow is out, I drop my hips on his arm and sit on it to trap it.
With my left arm, I swim my under their far arm and grab their elbow, with their wrist resting on the bend of my elbow (as in the arm crush).
I am also leaning towards their far hip and posting on the mat for balance.
Leaning like this, my left leg is light and free to move. I stretch it out over their head...
...then bend it behind and around their head, trapping their head and far arm in the circle of my legs.
As I do this, I fall back and let them come up to their knees.
I am now on my back and Trog is on his knees. I have his head and arm trapped in the circle of my legs, which is the start of the triangle, but at this point I am only crossing my ankles.
I could just close my triangle all the way right now, but that's just because I have long legs. So for all of you short legged suckers, here's how I would have you continue. I also use this sequence when trying to triangle guys with really broad shoulders.
I use my grip on the elbow to cross the arm.
Then I shove his arm all the way across with both hands.
With his arm across, I reach up with my right hand and grab my shin.
DO NOT grab your foot or ankle on the outside. You can break your ankle and heelhook yourself by pulling out here. It will also give you less leverage to break their posture since your ankle bends and your shin does not.
With a grip on my shin, I open my legs and step on their hip with my right foot. I keep my right knee squeezed tight to their shoulder so they cannot pull their elbow out that side.
This simple grip on the shin is what I consider the most important point to do to prevent them from posturing out to escape. As you work to close the triangle, never uncross your ankles without grabbing your shin first, and likewise, never let go of your shin without crossing your ankles (or closing your triangle) first. You need to pull down on your shin to keep constant pressure on them and break their posture.
Now I reach inside their knee with my left hand. This is another point that I think everyone should do. You can use it to turn for a better finishing angle, you can use it to sweep them to a mounted triangle if they try to stack, and it prevents them from slamming you if they stand.
Pushing on the hip with your right foot and pulling your head to their knee with your left arm, turn yourself perpendicular to them. You'll know you've got a good angle when you can look in their ear.
Keep turning, stepping on the mat to help if you need to, until your calf is chopping on the back of his neck. You don't want your leg on his back or shoulders at all if you can help it.
With a great angle on the neck, I close my triangle, throwing the bend of my right knee over my left ankle.
To finish, I pull down on the head, thrust my hips up and away and stiffening my back (not pulling him into me and bending at the waist, which helps him stack -- a detail I picked up from Dean Lister's movie) and squeezing my knees.
In my opinion, squeezing the knees is the most important detail to finishing the triangle that most people miss. Whenever I hear someone complain about how hard they have to fight to finish what seems to be a good triangle or say that the choke is a "slow one", I ask them to show me how they do it and they usually pull down on the head and lift their hips really hard, but not squeeze their knees. Once I add that detail, it becomes a very fast choke.
Here's a little variation I've been doing that turns this into an triangle-armbar combo.
When I go to underhook their leg...
...I make sure I reach over their arm, trapping it in my armpit.
Now when I lift my hips, they get to enjoy an armlock too.
Yes, I'm aware that my triangle isn't closed tight in many of these finishing photos. I didn't feel like making Trog suffer any more than needed.
God, I'm awesome.