Countering the Twister Pass for BJJ
Twister Side Control
If you have good training partners, there's a very good chance you've had your guard passed straight into reverse kesa gatame, or "twister side control." This describes a position wherein your partner elects to drape their arm over your body (unlike a Kimura, this bypasses your top arm completely), while switching their hips toward yours. This position can be considerably harder to escape than other types of side control (although, if you're stuck in side control, you might appreciate these unorthodox escapes).
What the Top Person is Doing
Here's a look at the half guard pass we're starting with, along with a common back take maneuver. Start by switching your hips on top, but underneath your partner's armpit, rather than like a Kimura hip switch position. From here, start walking your hips up so that you isolate your partner's inside arm, and then walk your foot up so that your trapped (right) shin is perpendicular to the ground. If you need to, you can wedge your left knee and shin in between you and your partner to help free your leg. Once free, your ambition is either to move to the mount or to take the back. The back requires hooking your partner's right leg with your right leg, and I prefer to get a lockdown from here (many other black belts do this without the lockdown; it's a matter of preference and security vs getting into the position faster). Now, just reach over your left shoulder (preferably after grabbing your partner's foot with your right hand), and roll forward, finishing the ninja roll back take, as amply described here.
Using the Lapel
Rolling in the gi offers a unique opportunity to counter this guard pass that isn't available in no-gi training (there are other options, though). As your partner starts to execute the pass (and you should see it coming a mile away by now), reach over with your own left arm (mirroring their position on you) and untuck their lapel, getting a firm grip on their jacket. This will keep them from turning and finishing the back take completely. While it's going to be difficult to stop your partner from getting their leg free to (partially) finish the guard pass, it won't be impossible for you to step over and get your own hook with your left leg, particularly if you use your free right arm as a stiffarm on your partner's pants grip, keeping them from stepping back. Now you've created what's essentially an "even money back take" situation: either person can get the other's back, with one caveat: you have their lapel. Now, build your base up as though to hip bump your partner over (and, indeed, if your partner doesn't react, just come up on top). As your partner responds, use the space they've created to scoot your hips out and execute your own back take.
Not So Fast (On the Back Take)
Be careful not to move too quickly through the back take, lest your partner simply pull their leg free and finish the pass. This is why I'm a huge fan of the lockdown all the way until you have the harness grip. A good way to see whether your angle is correct with regard to the "calf leg" on the lockdown is to try to execute a calf slicer on your partner. If you can't do it, they can probably get your back just as easily as you can get theirs. .
Which reverse kesa gatame do you prefer?
Two further things of note are worth considering. First, if your partner switches their hips "Kimura-style" (still considered reverse kesa gatame, but no longer "twister pass"), you need to execute this style of counter instead. This technique only works because of the specific arm position of your partner. Second, if your partner is already executing a ninja roll (you're a little late on the escape portion), you need to counter their ninja roll with this. Jiu jitsu is infinite in its complexity, and it's always evolving and changing, but the positions you'll arrive at from the techniques described herein are fairly predictable, at least in terms of the highest percentage moves your partner is likely to try on you. Work on these counters, and, as always, let me know how they're working for you!