The Development of Ozeki

Looking at the top division careers of future Ozeki

My goal for Ozeki Analytics is to look at sumo wrestling, and use the available data (and perhaps even build upon that) to answer various questions about the sport. We’ve already looked at what it takes to reach the rank of Yokozuna and Ozeki, but those inquiries start when the wrestler is already on the precipice of promotion to the two most prestigious ranks. A different question to try and ask is “how soon in a wrestler’s career can we predict that they’ll reach Yokozuna (or Ozeki, or Makuuchi, etc.).” This is a difficult question, but I think today’s piece will help us get closer to answering that.

Last week I took a look at the modern Yokozuna, how old they were when they debuted at the Makuuchi level, and how long it took them from their debuts to reach Yokozuna. That piece can be found here. Well this week I’ll be doing the same exercise but for Ozeki. Additionally, I’ll be comparing the data we have with Ozeki to Yokozuna, and attempt to see what those similarities (and contrasts) says about the kind of indicators that separate the men at the top from those destined to never quite reach that zenith.

To start with, the dataset includes 37 modern Ozeki¹ going back to the 1950’s (isn’t it cool that with sumo’s history I have to specify the century? Even baseball, the longest running American sport, only has seasons going back to 1871). So unsurprisingly, there are more men that topped out at Ozeki than Yokozuna, but the gap isn’t quite as wide as I expected; I naively assumed it would be closer to twice the number of O’s to Y’s whereas in reality it’s just ~1.35 times as many. It’s important to remember how special you have to be to even reach Ozeki. So let’s begin with the chart and the stats for Ozeki before we move onto the comparison between them and Yokozuna.

The basic stats

• Average age at debut: 21.8

• Median age at debut: 21.5

• Standard Deviation of above: 1.5

• Youngest debutant: 18.7 Takanohana (the older, and father to two future Yokozuna (talk about strong genes))

• Oldest debutant: 25.2 Kirishima (also the older, and current Kirishima’s oyakata/stable master)

After last week finding out that the oldest Yokozuna debut in Makuuchi was 23, there’s nothing in the above that surprises me so I’ll save the more substantive analysis for the comparison section. That said, unsurprisingly the average, median, youngest, and oldest age for Ozeki are all higher than their Yokozuna colleagues. Other than youngest, I’d assume they’re all higher, so that lines up well. Youngest isn’t particularly surprising, but I figured with a higher sample size there would more likely be an outlier on the young end.

So onto how many tournaments required to reach Ozeki from Makuuchi debut.

The basic stats (note I shortened it from: tournaments required to reach Ozeki after Makuuchi debut)

• Average tournaments required: 27.4

• Median tournaments required: 24

• Standard Deviation of above: 13.8

• Max tournaments required: 60

• Minimum tournaments required: 7

Sumo legend Tochinoshin (is my bias showing?) is one of two men who took 60 tournaments from his Makuuchi debut to reach Ozeki. There really are so many fun and notable stats about Tochinoshin; as discussed in the What Makes an Ozeki piece, he holds the joint record for most wins in an Ozeki run. Masuiyama is the other man requiring 60 tournaments, and he notably holds the distinction for oldest modern Ozeki debut.

And now charting the same for the Yokozuna.

Same stats for Yokozuna:

• Average tournaments required: 19.4

• Median tournaments required: 16

• Standard Deviation of above: 10.4

• Max tournaments required: 42

• Minimum tournaments required: 6

And now comparing the various numbers in a table.

So we can see quite clearly that the men destined to reach Yokozuna debut in the Makuuchi at a younger age pretty clearly. Furthermore, those destined for Yokozuna reach Ozeki sooner. Both of these are both aligned with what you would think, but it’s also nice to be able to put in concrete number the magnitude.

My goal at Ozeki Analytics in part is to use numbers to understand and predict sumo. The first couple of pieces gave us the tools to look at people shooting for the top two ranks, and to determine if their efforts are likely to be rewarded or not. With this piece, and more to come in the future, hopefully we can give ourselves the tools to determine who in the future will be the men to be fighting for Ozeki and Yokozuna.

I think I might start looking to categorize pieces as we’re starting to accrue enough that they fit distinct categories such as Development, Determining Rank, Previews, etc.

I also have a twitter account here. I only post about sumo so if you want to get some occasional light analysis, fun facts, chop it up with me there, DM, etc. please follow. I think we’re building a nice community across the platforms. Thanks!

Future Pieces

• When assessing Yokozuna runs, does it actually matter if you have a Jun-Yusho or is the Yusho actually required - lots of numbers

• Sumo Development

  • 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

1. Tochihikari on down are included if you sort based on Hatsu Dohyo here. Tochihikari debuted in 1952, but taking the median number of tournaments held annually through his career, it was actually 6, so I included him.