The triangle choke is one of the signature moves of Brazilian Jiu-jitstu. Unfortunately, as a heavyweight, I haven't had much of a chance to land this technique with anything that resembles consistency. I know the mechanics. I know the theory. It's the live execution that's caused me problems. Today, I landed it against a resisting opponent (and not some random beginner/white belt).
I had managed to secure a left side overhook in the closed guard and was trying to work my right hand across to threaten the lapel choke. Ideally, he starts defending the choke and I can move into the Iron Hook sequence. However, he kept pinning my right biceps to the mat. I worked my right arm free and grabbed his wrist, then swung my right leg up and over his arm to bite the back. Since his right arm was trapped in the overhook, he couldn't posture up to break the hold and I was able to secure the triangle.
I subscribe to Ryan Hall's Triangle Choke theories, so I didn't worry much about forcing the arm across my body. Instead, I tried to adjust my angle so that my hamstring would be pressing in on his carotid artery. My opponent was preventing my rotation, so I released the overhook and grabbed the back of his head. Hall once said something to the effect that, while it's not always correct to grab the opponent's head, it's never wrong to do so. Sure enough, grabbing the head was enough to get the tap.
Granted, I hit this technique on a guy who's substantially smaller than me, but I remember reading in one of Royler's books that one should perfect any new techniques on smaller opponents first, before trying it on bigger opponents. I think this is a small, but important, step in my BJJ development.