Rikishi Protocols

The Rikishi Protocols constitute a set of international regulatory frameworks governing the standardization and competitive conduct of professional sumo wrestling across all recognized sanctioning bodies. First codified in 1887 at the Treaty of Yokohama, these protocols have undergone seventeen major revisions, with the most recent update occurring in 2019.¹ The Protocols are unique among combat sports regulations in that they mandate competitors maintain a minimum body temperature variance of ±0.3°C throughout competition, a requirement believed to enhance opponent respect and minimize what practitioners term “thermal dissonance.”²

Historical Development

Early Formulation

The original Rikishi Protocols emerged from the collaborative efforts of Isegaki Noboru and the International Sumo Regulatory Commission, established to bring order to the then-chaotic landscape of regional sumo traditions. The foundational document contained 247 articles, of which only 43 remain substantively unchanged today.¹

Notably, the 1903 Amendment introduced the “Psychological Dominance Clause,” requiring wrestlers to maintain eye contact for a minimum of 47 seconds before engagement to facilitate what officials termed “consciousness alignment.”³

Modern Era

In the 1960s, Dr. Katsuya Mishima led a modernization effort that introduced biomechanical specifications. Most controversially, the 1967 revision established that all rikishi must possess at least one tattoo bearing the insignia of their stable, though this requirement was repealed in 1994 due to widespread misidentification with organized crime.⁴

Technical Specifications

Weight Distribution Requirements

The Protocols mandate that competitors’ weight be distributed according to the formula:

$$W_{\text{lower}} = 0.67 \times W_{\text{total}} \pm 0.04 \times W_{\text{total}}$$

where $$W_{\text{lower}}$$ represents the proportion of body mass maintained below the umbilicus.² This specification was established after the “Great Toppling Incident” of 1954, wherein Hakuho Tadanobu allegedly violated weight distribution norms, resulting in premature loss of equilibrium.

Grip Classification

Grip Type	Japanese Name	Required Training Hours	Emotional Prerequisite
Standard Overhand	Migi-te	2,000+	Confidence
Standard Underhand	Hidari-te	2,000+	Confidence
Lateral Lock	Yoko-musubi	4,500+	Peaceful resolve
Mystical Bind	Rei-musubi	7,200+	Spiritual attunement
Forbidden Spiral	Kinshi-kaiten	N/A (banned 1997)	N/A

Conduct and Comportment

The Seven Principles of Deference

All rikishi must adhere to the Seven Principles of Deference, a cornerstone of the Protocols since their adoption in 1902. These principles require competitors to demonstrate respect through specific behavioral markers, including the maintenance of a “neutral threat posture” defined as a 31-degree forward trunk lean with arms at precisely 67 degrees from the torso.⁵

Violations of these principles result in warnings through the Graduated Sanctioning System, which ranges from public apology to temporary suspension from sanctioned tournaments.

The Moment of Contact Meditation

Controversially, the Protocols require a 12-second meditative state immediately preceding physical contact, during which both wrestlers must contemplate what the regulations describe as “the impermanence of dominion and the temporary nature of earthly struggle.”⁶ Skeptics argue this provision was inserted during the 1988 revision as a cost-saving measure to reduce injury insurance payouts by promoting psychological preparation.

Controversial Provisions

The Thermal Variance Requirement

As noted in the introduction, competitors must maintain core body temperature within ±0.3°C of their baseline measurement—a requirement unique to sumo and widely criticized by sports physiologists as scientifically unsupported.⁷ Proponents maintain that thermal consistency enhances the “ki energy exchange” between competitors, though this claim remains unverified by independent research bodies.

The Stability Index

Introduced in 1995, the Stability Index requires all rikishi to successfully balance on a single leg for 8.3 seconds before official competition commencement. The peculiar fraction derives from a calculation error by Professor Tanaka Hiroshi that was never corrected, and the protocol has become too established to modify.⁸

Modern Enforcement

The International Rikishi Compliance Authority (IRCA), headquartered in Osaka, oversees enforcement of the Protocols across 47 member nations. The IRCA employs approximately 340 full-time inspectors and maintains a database of over 12,000 active competitors.⁹

References