Q:

Benefits of an X-Stop in Tae Kwon Do?

Whilst I've never practised an X-stop, I was wondering what the benefits of it are? The move consists of a jump, punctuated by the back foot being placed a head of the front foot, and behind it, forming an X shape.
It seems like it would put you off balance, but it may be good for turning? I don't know.

A:

You should actually be able to land quite on balance in this stance: get your instructor to check how you're placing your feet. Make sure your knees are bent and you're dropping your weight low, but without bending your knees so low that you lose strength in the stance.
I would defer to someone more experienced than me, but I think of the main advantage of the stance is it lets you deliver power forward from the jump while enabling you to become immediately grounded and mobile. From the x-stop, you can drop back into a sparring stance, or easily turn in either direction, or even rotate through 180 to defend against an attacker behind you.
In the palgwe form I linked in an earlier comment http://www.youtube.com/watch?v=MNkeTjs833I I think the point is that the supported-uppercut finishes an opponent, and the student is then ready to answer an attack from any direction: in the form, it comes from the right.

A:

Looking at this motion, I see a few potential interpretations of this motion.

The back foot can act as kind of a foot check while jumping forward
The crossed position has an inherent coiling that can help with turning.
Though it's not common in Tae Kwon Do, I see how this position can transition to a scissor style take down used in silat and other styles.

A:

There are a couple of benefits of the x-stance (or x-stop as you call it).

Reach. If you are in a middle or front stance and you simply slide forward, your body weight and torso are centered between your feet (Mostly, there is some percentage difference in weight distribution, but for the purposes of this they are equal). Now, your torso is 6" to 1' or more behind the front foot of your stance. Slide your rear foot up into the X stance, and you gain that foot or so of reach.
Follow up strike. You are pre-tensioning the lateral muscles of your leg for a follow up side kick with your front leg. Because of the angle, your body already wants to release tension and move the front leg forward, so this gives a bit more speed and power to the kick. (And, as mentioned above, you are already much closer and not having to move stances to perform the kick.)

Now admittedly, the techniques will be slightly weaker because you aren't coming from a solidly grounded stance, but the reach may or may not make the x stance worth consideration in a particular situation.

