How to Set Up a Crucifix for BJJ
Virtually Check Mate
The crucifix in BJJ is virtually check mate, but it's not a scoring position like mount or back. In other words, you can go through all the trouble of setting up the position, and if you don't finish your opponent, you won't necessarily score a single point all match long. However, the efficacy of the position more than makes up for this, as you can attack both arms and your partner's neck, while they are going to have a very difficult time defending any of your attacks. Here are three different ways to get into the crucifix position, starting with the most fundamental method, and gradually increasing in complexity.
The Fundamental Turtle Attack
Setting up the crucifix from the turtle is the logical starting point, just as you might first learn how to take the back from here. Start on your partner's left side, and slide your knee in between your partner's left elbow and left knee, driving downward along their hip and then ribs. Ultimately, you are looking to control this "inside space." Mirror this on the opposite side of your partner by grabbing a "one on one", a frequent precursor to the Kimura. Using your left knee, bring your partner's left elbow forward, and then hook it with the heel of your left foot, dragging it back toward your knee. Now feed their arm to your back leg, so that you can sit on your leg, keeping their arm completely isolated. While you may find it easy enough to simply set up the rear naked choke from the turtle, the "shoulder roll" forward (over your right shoulder) really helps to open up your partner's neck, and it frees you up from the constraints of gravity, so you can use all of your limbs to attack your partner's neck or arms.
The Low Single Defense (Drape)
This next set up starts on the feet, but quickly mirrors the previous turtle attack position. Start with your left leg forward, and have your partner set up a single leg takedown. Reach over with your left arm and hook their arm, gripping the Kimura. Be sure that you don't allow your partner to grab your far leg, transitioning to a double leg takedown. Instead, continue to curl your left (trapped) leg back toward your center of balance, and then start bringing your partner to the ground. Once you are on top of your partner, and you get your leg free, you are able to step around behind your partner, replicating the same position shown from the turtle.
From the Bottom
The best pass to counter straight into a crucifix is easily the over/under guard pass. If you're sitting up, as your partner tries to drive you flat and place their head on the opposite side from where they intend to finish the pass (and you can bet that a good passer will do this 10 out of 10 times), it's important that you immediately redirect their head to the same side where they're headed. Quick note: there are some additional variations covered in this video that weren't shown in How to Defend the Over/Under Pass Defense (and Set Up a Crucifix), so even if you're familiar with those techniques, you may appreciate the additional options shown here. Once their head is redirected, the name of the game is effectively to recreate the previous drape and turtle positions. If you can simply perform an adequate "Trail Arm" catch, you're going to arrive where you need to be, with both of their arms completely trapped, and with you ready to finish the submission of your choice.
Favorite crucifix set up
You can set up the crucifix when you're already on top, as shown in the first technique; when you are neutral (both on the feet), as shown in the second technique; or when you are coming up from the bottom. With such a versatile technique, you might think we'd be flooded with different explanations on how to set the crucifix up, but that isn't the case. Think about the techniques systematically, and don't be afraid to play while you are training, and you'll come up with your own viable options. As always, keep me posted!