How to Escape an Armbar (in the Gi)
Time is Almost Up
Visualize this: you're stuck deep in an armbar from the top position (you're on the bottom). With just a split-second of freedom before your arm gets straightened, you grab onto your lapel with your trapped arm. What happens next will be determined by a few contributing factors: how good your partner is at finishing the armlock, how good at you are escaping, possibly how tired you both are, and possibly what has happened during the roll leading up to this event (think: sport BJJ, and one of you is up on points with a minute to go). What you can control from this is what we'll focus on here: how good you are at escaping. Here is a high percentage defense and escape you can start working on right away.
The Initial Grips
When you get caught in the armbar finish position, there are several possible defensive grips you might use (either willingly, or because you don't have any other choice). These include, but are not limited to: palm-to-palm, the RNC grip (both behind and on top of their leg), the "mummy", and hiding your hand inside your thigh. While all of these have a place, the main focus here is the lapel grip, so start by gripping your lapel with your trapped hand. If your right hand is caught in the armbar, this means that your left hand will now be freed up. Grab your partner's right pants leg inside of your partner's knee, and slide your left elbow under your partner's right leg (but but sure not to swim under with your hand, unless you enjoy being triangled!). Now you're set for the next steps.
Trapping the Foot
Once you have your grips all set, the name of the game is going to be trapping their right foot in between your legs. If you can elevate your partner's foot (carefully! remember the triangle), you can often simply shove their foot into your guard and go from there, but most people are going to make this as difficult as possible. Instead, try walking your legs around to the side so that you can position your hips under their foot, and then just close your guard around their foot. You essentially have a crappy sort of deep half guard here, and you can make finishing the armbar very difficult (even if they use a grip break to get your arm free). Why? In a nutshell, their knees can't pinch together to isolate your arm (or at least, you can make them pinching their knees very, very difficult). Finally, you can start to turn in toward your opponent. Sometimes it is possible to stack from there, but generally, you'll need to grip their pants (use the same hand you used to initially trap their foot), and then sneak your head out from underneath their leg.
Putting It All Together
You can break this escape down into three parts. First, you need to get your initial grips. Remember, your right hand gets a strong lapel grip, neutralizing the immediate threat of the armbar finish, and your left hand grips inside of their knee, while your elbow makes its way underneath your partner's foot. Second, you need to trap their foot. This can be accomplished either by simply stuffing the foot into your guard, or else by walking your hips out and simply keeping their foot from following you. Third, you need to come up on top (generally, you'll need to sneak your head out from underneath their top leg). This third step definitely comes with a caveat, as you can do a variety of different things, including something like a waiter sweep that I will almost definitely cover in a future tutorial.
Tougher submission to escape?
Counters to Counters
Always keep in mind that for every escape, there is a counter, and you're likely to encounter someone good at finishing the wristlock when you grab the lapel initially (you can definitely adjust and survive anyway, but don't get discouraged initially). Your chances of tapping against a savvy opponent are, after all, very high from a solid finish position. Nevertheless, this escape series serves me well against very good folks, and I hope it does the same for you! As always, please let me know if you are able to use this escape successfully.