Are regional basho really more chaotic?

Conclusion

The idea is not supported. The upset rate was 35.7% in Osaka, Nagoya, and Fukuoka, versus 36.3% across Tokyo basho. Venue changes alone do not appear strong enough to move Makuuchi results in a meaningful way.

Methodology

Period

2000 Hatsu Basho～2026 Natsu Basho

Sample

Makuuchi bouts with a strength-index gap of 40 or more before the bout

Sample size

Regional 16,140 bouts, Tokyo 16,142 bouts

Calculation

Number of losses on the higher side ÷ Number of samples. Local areas 35.7%, Tokyo 36.3%

by basho

Hatsu Basho37.9%, Natsu Basho34.9%, Nagoya Basho35.5%

How to read this

Strength index is calculated only before the bout. Differences in seasons, Banzuke, and rikishi compositions other than the venue will remain.