As I write about basic strategy, there are many concepts that come up that need more explanation. Chushin, or the centre, is definitely a very important one and deserves its own article. Understanding chushin is the key to knowing whether there is an opening, an opportunity, to cut your opponent.
Chushin is written with two kanji: chu (middle) and shin (heart/mind). It means the core, the focus, the pivot. We might say in English, "going to the heart of the matter." This is a good way to think of chushin in kendo.
How big is chushin?
Chushin is partly real and partly abstract: partly a thing you can touch with your hand, and partly an idea.
The idea part is this: chushin is sometimes called "the centre line", an imaginary line between you and your opponent. When you face your opponent, only one of you will be able to point the kensen (tip of the shinai) at the other's throat. Chushin is an imaginary line between the two of you, between your throat and your opponent's. Chushin is difficult to perceive because it is dynamic, it never sits still.
The concrete, or real, part is this: chushin is exactly as wide as the tip of the shinai. The actual tip of the shinai, the leather cap that can wear out and needs to be checked regularly, is called the sakigawa. The sakigawa is about 3cm wide. Hence chushin is 3cm wide.
How can something that is an idea also have such a specific size?
If you think about it, it becomes clear. Only one person can control chushin at a time. The sakigawa is 3 cm wide. Therefore if your sakigawa moves away from the centre by 3cm or more, your opponent can now point at your throat, controlling chushin, the centre. Therefore chushin = 3 cm.
A quick but important exercise
- Go get a ruler and a shinai.
- Have a look at how long 3 cm is.
- Hold your shinai in chudan no kamae and practice moving the tip side to side, but make sure the movement is less than 3 cm.
- Take notice of how small a movement it is. Think about how often you might wave your kensen around more than that when facing an opponent in jigeiko.
An opening is when you perceive that your opponent's kensen is not pointing straight at your throat. Being able to perceive chushin accurately, and especially, being able to know whether you or your opponent is controlling it is important. Not only that but being able to be aware of this all the time is the key. This is very difficult to do.
At the beginner levels, people use shikake waza like harai-waza or ose-waza unecessarily because they don't realise that they are already controlling chushin. If your opponent's kensen is slightly to one side, or slightly high, then you can often cut them without any prior waza. If your opponent's kensen is too high for example, then they have opened their kote.
Next time you are facing an opponent, whether it be during kihon practice, uchikomigeiko, or even a match, pay close attention to whether their kensen is pointing directly at your throat. This kind of observation of your opponent is vital if you wish to develop strategy and learn how to overcome them.
Remember: only one person can control chushin at a time.