Does decline begin after age 30?

Conclusion

Makuuchi win rates step down from 52.8% at ages 20-24 to 50.2% at 25-29, 47.6% at 30-34, and 43.7% at 35 and over. Selection matters, but the downward slope is clear in the results.

Methodology

Period

2000 Hatsu Basho～2026 Natsu Basho

Sample

Makuuchi Kuniorikishi's participation record where you can check his date of birth

Sample size

92,298 people number. 29 years old is number 8,570

By age

20-24 years old 52.8%, 25-29 years old 50.2%, 30-34 years old 47.6%, 35 years old or more43.7%

Calculation

Number of wins / number of appearances at each age. 29 years old: 49.3%

How to read this

Rikishi who rise to Makuuchi Kunio at a young age include the selection effect of being strong from the beginning. Age is not the only causal effect.