One Inch Distance


Life And Death in the Thickness of Paper.

by Rick Rowell

Distance - Life and death in the thickness of paper

In the duel between Miyamoto Musashi and Sasaki Kojiro made famous in the novel Musashi by Eji Yoshikawa, Musashi’s headband (hachimaki) was cut by Kojiro’s sword the same instant he killed Kojiro.

Kojiro may have died smiling, thinking he had cut Musashi.

Musashi, however, fully understood the concept of distance or Interval (Ma-ai) and its relation to time. Kojiro’s sword was a fraction of an inch too far away, but Musashi’s was not. As Kojiro was famous for the use of a longer sword, Musashi used a wooden sword carved from a boat oar—just a little bit longer.

The ability to judge the distance between your opponent within one inch or less can mean the difference between life and death.

There are a number of distance concepts used in the martial arts, but I am going to focus on two that are essentially the same principle and related:

    • Issun no Ma-ai – literally “One Sun Interval”. A sun is an old Distance - definition of SunJapanese unit of measurment a little over an inch long (1 sun = 3.03 cm). For the sake of clarity let’s translate it as “One Inch Interval”


  • Kami Shitoe – can be variously translated as “The difference in the thickness of a piece of paper,” hair’s breath, razor’s edge, paper thin, or nick of time.

The two ideas are essentially the same principle. To illustrate the principle, the figure below is a stylized overhead view of an attacker and defender. The person attacking is the black circle.

A. Shows two opponents facing each other from a slightly Toma (Far Interval ) distance—the starting position of the engagement.

B. Shows the defender maintaining the same distance from the attacker by shifting back at the same rate the attacker moves forward. Tactically this gains no advantage because it maintains the distance the defender will have to cross in order to counterattack. Any counterattack takes longer—because you have to cross a larger gap, and that takes time. A large spatial gap also gives your opponent the opportunity to re-take the initiative (Go no Sen) from you, or at the very least to strike you at the same time you strike him (Aiuchi, mutual striking). This type of movement (maintaining distance) can be useful if you are not ready to engage and want to remain at a safe distance outside the opponent’s Hitting Distance (Uchi no Ma-ai).

C. Shows the principle of “One Inch Interval” or “Difference in the Thickness of Paper.” Reducing distance by controlling movement backward to just outside the attacker’s range, means you are still a hair’s breadth out of range—in other words, safe. Tactically, you gain advantage because your counterattack does not have as far to go to reach the opponent and is hence faster.

D. Shows the same concept only by Shifting to the side or Entering (Sabaki or Irimi) and actually moving toward the attacker and just evading the attack by the “thickness of a piece of paper.” Tactically this makes the counterattack faster yet again.

Distance Concepts

The Issun no Ma-ai/Kami Shitoe concept can be used with any timing concept (Go no Sen, Tai no Sen, Sen no Sen) whether you block or not. The important aspect of this principle is that it is used to tactically retake initiative and make it very hard for your opponent to deal with a counterattack that is both compressed in time and space.

One Inch Distance (Issun no Ma-ai) is a critical concept in combat. It is not wasteful of time or distance, can be used with all timing approaches, and—no matter how strongly an opponent attacks, a miss is a still a miss. A miss by only one inch leaves you alive just as much as a miss by two feet, but the smaller miss leaves you in position to immediately exploit the opponent’s weakness (Kyo) that inevitably follows his missed attack.

Kami Shitoe is sometimes referred to as life on one side of the paper and death on the other and hence the idea of a razor’s edge between life and death.

Miyamoto Musashi in his book the book of five rings (Go Rin no Sho), written in the seventeenth century uses a very similar concept when he discusses the Spark of Flint Hit (Sekka no Atari to iu Koto).

“The ‘Spark of Flint’ means to strike with a great deal of force when the opponent’s long sword and yours are close enough to be barely touching, but without raising your long sword in the slightest. This means cutting quickly with hands, body and legs—all three cutting strongly. If you train enough you will be able to strike strongly.”

Musashi’s example shows how by lifting the hands the sword moves away from the opponent and increases the distance away from the opponent. Cutting immediately reduces time and distance, but you have to practice to become sufficiently strong enough to cut with force.

In unarmed martial arts such as Karate, the principle is no different. Moving just out of range of a punch or kick, then immediately countering is a common tactic in more experienced Budoka than in beginners.

The principle of minimizing or closing distance is as old as warfare, but you can challenge yourself to use this concept in other ways. Can you find examples in negotiation, hockey, formula one racing, or baseball?

The principle of “One Inch Interval”  or “The Difference in the Thickness of a Piece of Paper” can produce tactical advantage by manipulating time and space to stay just out of range of your opponents attack, and hastening contact with a counterattack.

There are many other distance and timing principles used in the martial arts.

Consider Budo Theory: Exploring Martial Arts Principles as a reference to learn more.