The Development of Yokozuna
The Development of Yokozuna
Looking at the top division careers of future Yokozuna
As I write this in January of 2024, Onosato is currently fighting his first tournament in the Makuuchi, the highest division of sumo. He is considered one of the top prospects in sumo wrestling history and reached the top division in just 4 tournaments.
Let’s play a game: right now, I want you to think to yourself this question, “how many future Yokozuna in the modern era1 made their Makuuchi debut older than Onosato is in this tournament?” That’s a pretty tough question without more context so I’ll tell you that for purposes of this exercise there are 27 modern Yokozuna, starting with Kashiwado. I’ll give you one final clue; Onosato is 23.5 years old (born in June so almost perfectly a half year) at the time of his Makuuchi debut.
Got your answer to the question “How many of the 27 modern Yokozuna, starting with Kashiwado in 1961 debuted at Makuuchi older than Onosato (23.5)?”
Perfect. Now for the answer.
Zero. Yes, that’s correct. If Onosato is the next Yokozuna - then as of me typing this out - he’ll be the oldest Makuuchi debutant of modern Yokozuna.
The point of this post isn’t that Onosato will never be a Yokozuna because he debuted at an elderly 23.5 (the man is nearly 24! He’ll be able to rent a car soon!). Rather what happened was in looking at the path Yokozuna take to reach the apex of sumo wrestling I found out this rather surprising statistic.
I’ll look at Ozeki on a similar basis in a future post, but I ran the numbers and of the 37 modern Ozeki2, 9 (nine!) out of 37 debuted at 23.5 or older in Makuuchi. 0% vs ~25%!
Now let’s actually dive into the numbers further starting with a chart of age at Makuuchi debut of those Yokozuna.
The basic stats
Average age at debut: 20.8
Median age at debut: 20.6
Standard Deviation of above: 1.40
I’ve looked back through the data and spot checked and done various other basic checks to ensure I have this right but this data really blew me away. If you find one of these is wrong, please let me know because the average age of Makuuchi debut at Yokozuna might be the most surprising statistic to me yet!
But today we’re not just looking at what age Yokozuna debuted in the top division at; to explore another dimension, I also looked at how many tournaments it took those future champions to reach the top rank from their debut. I think using Makuuchi debut in this case is a little more helpful than just sumo debut in general. This puts all the men on an equal playing ground whereas they didn’t all debut in the same initial division.
So Taiho, the quickest man to reach Yokozuna after his Makuuchi debut took only 11 tournaments to do so. On the opposite end, Kisenosato required 73 tournaments to reach Yokozuna from his debut. So here’s the chart.
Boy, looking at Futahaguro’s numbers there, it becomes even more obvious he could have used a bit more seasoning.
The basic stats (note I shortened it from: tournaments required to reach Yokozuna after Makuuchi debut)
Average tournaments required: 33.4
Median tournaments required: 28
Standard Deviation of above: 16.4
As you can see in the chart and the standard deviation, there’s a little bit more variance here compared to average age. Also, as Kisenosato is almost a full standard deviation above Kotozakura in tournaments required, I ran the numbers again excluding him.
Average tournaments required (no Kisenosato): 31.8
Standard Deviation of above (no Kisenosato): 14.8
So that does make a bit of a difference.
But there’s even more we can do with this data. I took the correlation of these two data series to see how closely related they are.
The correlation between age at debut, and tournaments required to reach Yokozuna is -.11
In other words, the younger you debut, the more tournaments required to reach Yokozuna. That makes anecdotal sense, but with a sample size of 27, I don’t attach too much significance to it.
One of my larger goals with this project at Ozeki Analytics is to use numbers to answer, model out, and understand various aspects of sumo wrestling. When I think of what I want to understand, chief among that is the idea of how wrestlers develop.
How wrestlers develop is a multitude of questions such as when wrestlers reach their peak, if we can predict when that is, if we can predict at various points in time (such as at Makuuchi debut) how good a wrestler will be, and many more.
What are we to conclude from this data? I think the obvious takeaway is that Yokozuna are very special men and as such, make their debuts in the top division incredibly young. Older top division debuts in sumo aren’t strange; Tobizaru, a current top division mainstay who has even reached as high as Komosubi, made his debut at 27. Kirishima (the older one) debuted aged 25 and made Ozeki. But no man has been older than 23 and made Yokozuna.
But I also think that looking at how long from debut to Yokozuna gave us some more important data and context. The standard deviation of wins required is 16.4. It took 6 men fewer than 16.4 tournaments to reach Yokozuna from their top division debut.
With this in mind, I feel pretty comfortable saying the following:
There is no standard amount of tournaments required to reach Yokozuna. If a wrestler has been in the top division, even up to 10 years, there’s a chance they can put things together and go on a rope run to reach the top.
Reaching the top division at a more advanced age (older than 23) is almost certainly an indication that a wrestler will not be a future Yokozuna
I’m sorry Tobizaru fans, but I’m declaring in this post that he will not be a Yokozuna. However, I am willing to hold out hope, and one day update this post and my data with a record breaking Onosato.
Future Pieces
When assessing Yokozuna runs, does it actually matter if you have a Jun-Yusho or is the Yusho actually required
Sumo Development
How many tournaments to reach Ozeki from Makuuchi debut?
How many tournaments does it take to reach Yokozuna from Ozeki?
There’s way more to be done; however the above data I currently have reasonable access to
A look at the most impressive tournament by Ozeki as a group ever
Featuring 3 future Yokozuna, the 4 of them averaged 13 wins and won the Yusho and Jun-Yusho
Tournament winner statistics
How many wins is a “weak” tournament win vs a “strong” one
A deep dive into Tochinoshin’s Ozeki run and the 3 other men who tied him with the 37 wins over 3 tournaments to reach Ozeki
Longer term: constructing an ELO ranking of wrestlers in the Makuuchi
Preliminary coding work is started and it’s looking viable so it’s just a matter of putting my nose to the grindstone
https://www.stablemasters.ca/ actually has this already and it looks great. Hopefully I can match some of the great stuff there
Longer term: my dataset is currently just Ozeki and Yokozuna so I’m looking to further refine the existing code and pull the full Makuuchi ranks and possibly Juryo too to look at development paths for wrestlers
Longer term: looking at volatility of win totals for wrestlers
Potentially related: looking into injuries
If you have any other ideas, feel free to message me on any of my channels and I’d be happy to credit if it does become an article
The only really borderline Yokozuna were Tochinishiki, Wakanohana, and Asashio. 1958 was the first year with the 6 tournament basho system (1957 had 5, and 1956 had 4, and 3 or 4 was generally the rule before then). I took the number of tournaments that those men participated in each year and then took the median. Each of them had a median less than 6 (in fact 4 was the highest median) so I excluded them. I feel this is relatively fair as any method could be.