It’s the magical time on the sumo calendar again, we are anticipating the release of the banzuke for the upcoming Aki basho in about 6 hours from now. The sumo world is waiting to see how they sorted the mess of COVID kyujo out, and where yusho winner Ichinojo ends up. While we are waiting, feel free to take a look at some forecasting from Team Tachiai’s resident master forecaster, lksumo.
The banzuke is a crucial element of any basho. It’s the ranking list for each tournament. While it’s formally decided a few days after the end of the previous tournament, it’s not printed out and provided to the public until two weeks before the tournament. One downside is, it’s static. It is not updated during a tournament with results and it shows a wrestler’s current position and not their history or trajectory. The illustrated banzuke is a way to put a face to a name (or a back-side to a name, depending on which illustrated version you’re looking at).
I’ve tried to address that here by taking the basic banzuke and adding more data on each wrestler’s career as well as their record. Their names are colored by whether they were kachi-koshi or make-koshi. It’s not clean and finished yet but I think it’s time for a public beta release. I’ve played around with it enough on my own so it would be nice to hear from others.
The important thing to keep in mind is that I am targeting every sumo fan with these dashboards, regardless of your love for data and technology. I joke about the Kyokai and their fax machines, yes. But I know a lot of technology freaks people out. That’s not what I’m here for. I’m here to use appropriate innovations to provide additional access to more information. In this case, the ability to mouse over a name on the banzuke gives more information about the wrestler. I’ve also put three dropdown filters to allow users to select a banzuke, a division, and/or a stable.
As I mentioned above, I have three dropdown filters under the title: banzuke, division, and stable. The default banzuke here is the most recent Nagoya basho while the other two are set to “All”. I don’t encourage setting the Division filter to all, unless you have selected a particular heya. When looking at a stable, it’s nice to view all their members in one screen. Please feel free to cycle through the multiple tournaments. I’ve got the banzuke from 1958 to present because that’s the start of the 6 basho era. I need to put a massive caveat there, that the data for wrestlers’ careers starts there, 1958. So if a wrestler was active beforehand, well, I don’t have that. I know that will be a bummer for folks interested in the careers of past Yokozuna.
If you mouseover the name of a rikishi, you’ll get a flyover screen with additional details about the wrestler, like their stable and hometown, as well as the length of their career. But for me, the part that I find the most useful is the line graph which tracks the wrestler’s path up, and down, the banzuke. I’ve had this visual on other dashboards before. What I’ve been able to add is the kyujo tournaments (in red) and yusho (the golden kanji character for YU).
We can see here that Ironman Tamawashi has not had a tournament kyujo. (He’s actually never had a day kyujo until this past tournament and the Covid kyujo.) He’s also won three yusho: in Makushita, Juryo, and the Makuuchi top division. I’m still working on getting kinboshi and special prize data but this is already pretty busy. If I get that data, I may just list it above the chart. Unfortunately, it’s a bit busy as it is.
I’ve called it the Kitchen Sink because I feel like I’ve throwing all the data into this, and I’ve got more to come. For active wrestlers, I have the height and weight data from the Kyokai as well as style preferences.
I am very interested in getting feedback for this visualization and any others. I’m thinking about hosting a Twitter Space or Zoom or something to help walk people through the dashboard as well as to talk about the data. At work, I use Teams and walk people through with the help of PowerPoint and screen shares. I don’t think PowerPoint would go over well here. I find sharing pdf and pptx files on the internet highly sus, anyway. So I’m not going to do that. If I post a video, it’s not very interactive and I can’t answer your questions, live. We record sessions at work but those aren’t as effective as live-learning. A Twitter Space would just be audio, I think, so that may not be the best option. But sometimes it’s nice to have a quick chat about data.
Well, until I figure out a better option, feel free to leave feedback in the comments. If you experience any problems, notice any bugs, let me know.
While we put together our own predictions of the next banzuke, inevitably we’ll come across some real head scratchers. Tim gave me some insight on Twitter that kyujo complicates this banzuke guessing-game by robbing us of our zero-sum game. There will be absences, like those of Terunofuji, which will not have corresponding wins among the rest of the field. So, inevitably, we get some wild swings especially in the mid-maegashira ranks. I’ve attempted to visualize those swings.
I’ve been toying around with a way to visualize this in a way that will be helpful for trying to predict the banzuke. So what I’ve got right now is a little dynamic heatmap that takes each wrestler’s starting rank (going back to 1958 and the modern 6 basho, 15 match-day calendar), and plots it along side where they end up on the next banzuke.
I don’t have 2022 data in here yet and that’s not really a priority at the moment. In fact, you may want to filter the years to exclude the “Covid Years” because this shows the effect of Covid Kyujo. The histogram of wins shows that there’s a bit of skew, a fat tail there, for wrestlers with zero wins as we see that instances of full kyujo occur more often than wrestlers getting one or two wins in a tournament. Click on that 0 win bar, and the outliers are apparent as some wrestlers preserved their rank with zero wins, while most dropped dramatically. Around M5, they’re all dropping to Juryo but we can see that even wrestlers in the joi have fallen out of the top division by posting zero wins.
“Well, what does this mean for my predictions, Andy?” There are several things we can learn. For example, if a wrestler has 6 or 7 wins, or even 11 or 12 wins, there’s a very narrow band of probable ranks to put that wrestler. However, if a wrestler has 8 or 9 wins, this appears to be where the art comes into play. With 8 wins, a wrestler at Maegashira 11 has been promoted anywhere from Maegashira 2…to staying on that same 11th rank. The heatmap shows us they tend to fall around M8 but specific circumstances can make for wild swings.
We’d expect a relatively normal distribution of wins but there’s actually fewer instances of 7-wins than expected, even fewer than there are 6-win records. There’s also a bit of a larger-than-expected spike for 8 wins. When filtered for 2012-2021, the distribution appears more normal. There’s still a spike at 8 wins but with the importance of that 8-win threshold on a sekitori’s career and income, it is to be expected, especially if one is possibly injured; Get that 8th win and then go kyujo. But is this evidence that yaocho has been rooted out of the sport, or at least that the situation is better than it was decades ago?
Now, how did this help (or not help) my banzuke guess? Well, we won’t really know until the banzuke comes out but I feel like I did my best. I wasn’t as leery of over-promoting wrestlers with 8 and 9 wins, of which there were several. It was still very difficult to place Takayasu. From his position he could very well contend for a sanyaku position but I had to settle him at Maegashira 2 East. This would be a historically low position for M7 with 12 wins. He was in this same position after Hatsu 2013 and was promoted to M1. Unfortunately, I think Ichinojo and Kiribayama will just pip him to those top rank-and-file slots since Takayasu was out of the joi-jin.
I think this did help me feel more confident in how I placed the Juryo promotees, and who I picked, as well. But there are definitely several who I am really not sure about. I had Shimanoumi as high as M5-6 for a while but I am more comfortable with this version. Tobizaru gets a decent bump but he’s certainly not far out of the ordinary.
I have published the visualization below here, just click the “Read More” link if you’re on the homepage. If you clicked through directly to the article from Twitter, it should show up by default, I believe. Anyway, I don’t want it to always load for everyone because I know the Tableau vizzes can churn for a bit. So for those just browsing on the home page, this won’t kill anything.
Anyway, if you click through and play with it, I would advise clicking the button to view it full screen, down toward the bottom right of the visualization. It makes it much easier to work with.
I’m also planning some updates. In particular, I want to include a parameter for the number of kyujo bouts in makuuchi. And I’ve got the data to do this for the lower divisions.
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The starter’s gun for the Osaka basho has sounded, when the Haru banzuke was published early Monday morning in Tokyo. It comes as no surprise to Team Tachiai that our own lksumo has once again scored many direct calls on the new rating sheet. Well done sir!
Feel free to include your favorite in the comments. We are quite excited that the next tournament is less than 2 weeks away.