"Shin-on-Shin" for Brazilian Jiu Jitsu (BJJ)
"Shin-on-shin" position is a subset of several different types of guard, and arises as a great leverage point and as an entry into various submission set ups and other types of guard. The technique is prominent in sport jiu jitsu today and has been around for a number of years. Though it's only recently that much regional or national attention has been paid to the position as a whole.
Here, let's take a look at a few common techniques and situations where shin-on-shin can be useful.
Bread and Butter Basics
A very simple situation wherein the shin-on-shin position becomes useful is a simple "combat base" entry from closed guard.
When your partner has their right knee forward, attempting to either knee cut pass or leg staple guard pass, the general idea is to hip out to your left, creating enough space for your left foot to pass in front of your partner's right (lead) shin.
Your goal is to create something like a 45° angle between your shin and their shin. Now just pull them forward, creating the ability to drive their lead knee to the ground, facilitating a simple closed guard recovery.
Another high percentage use for this technique is to enter into X-guard by shooting your leg underneath your partner.
This time, scoot in close on your butt toward combat base, once again with their right leg leading and your left leg connecting. Next, hug their leg close to you with your left arm, keeping them from retracting their leg (once you have that 45° angle, you don't want to retract your own foot in any sense).
From here, you need to pull your partner on top of you, carrying their weight on your body so that their foot isn't anchored to the floor any more. This means you should be able to kick your left leg straight through, entering into any variety of X-guard (or modified X-guard) positions and techniques.
Setting Up a Triangle
A somewhat more advanced version of the closed guard recovery, the shin-on-shin entry into the spider guard triangle still operates on the same premises.
Start with a spider guard "biceps control" with your right foot, while maintaining a same-side collar grip with your left hand in order to control their posture. To counter their combat base, set up the same shin-on-shin position as before. Stay tight to them by pulling them in with the collar grip, then kick out their knee to the side, helping facilitate their knee dropping to the mat. Use this moment to jump over for the triangle set up.
Into Deep Half Guard
Once again, your partner is entering via combat base, attacking your open guard. Sit up and connect your instep with their instep ("shin-on-shin"), and hug their leg close to you, like the X-guard entry.
This time, push your partner's upper body away from you while you lean outward, hugging their foot and leg close to your body, once again facilitating taking the foot off the ground and keeping it as light as possible. This time, go straight into deep half guard without kicking your leg straight through.
You can often come straight out the back door, ending up either on your partner's back or on top, finishing the sweep.
Deep Half, X-Guard, or Closed?
Like all other types of modern guard ideas, shin-on-shin is being studied widely, and combinations and counters are a huge part of the evolution of the position.
Play with it yourself and come up with your own innovations. We are all involved in a rapidly evolving body of jiu jitsu techniques, and we can all contribute to them. But it all begins with understanding of the basics of the position. As always, let me know if any of these techniques work for you!