I’ve focused quite a bit on mathematics in my first couple of posts, so I wanted to formulate a minor Natsu banzuke prediction in this post based more on history. As I detailed in looking at the shift in first week results, much of the change we’re seeing has come down to those at the Sekiwake rank punching above their weight. And much of the debate around the new banzuke seems to be focused on how many such ranked rikishi we may see as we prepare for the next tournament in Tokyo.
So let’s go back 45 years and look at an interesting turn of results that led the banzuke to shift from the standard 2 Sekiwake up to an incredible 5: Continue reading →
Now that Haru is in the books, I thought it might be fun to dig back into the maths and introduce an equation to work out which of the Heya, or sumo stables, are the real power players at the top end of the game. If it looks like we’re on to something, then perhaps it’s something we can revisit after future tournaments as well. As this is our first post on the subject, let’s tackle the methodology and then we can get into the rankings for Haru and analysis. So, whose chanko nabe tastes the best?
In order to work this out, I built a points system which can be loosely based around these Three R’s: Ranking, Results, Rewards. Very simply put, a heya should get points for the level at which their rikishi perform, the results they achieve, and the rewards which bring them glory. All good positive stuff.
Points are awarded for fighting at the following ranks:
Maegashira 1-5: 10
Maegashira 6-10: 8
Maegashira 11+: 5
Juryo 1-7: 2
Juryo 8+: 1
I separated Maegashira and Juryo into separate points categories as rikishi at the various ends of these ranks tend to have vastly different schedules. Fighting at a Maegashira 2 rank and having to face the likes of Hakuho is a bigger accomplishment than fighting at Maegashira 14. And being Hakuho is an even bigger accomplishment. So the points should be awarded accordingly. This obviously could be scaled up to accommodate even lower ranks, but it makes sense to start awarding points based on the world of professional sumo.
I added 5 points for scoring a kachi-koshi in makuuchi, and 3 points for achieving a kachi-koshi in Juryo. I did not subtract points for scoring a make-koshi. Again, the rationale here is that fighting at a particular rank is the achievement. Achieving success at that rank should be recognised. Achieving failure at that rank will be reflected by the lower rank the rikishi will receive in the next banzuke, and therefore the lower score that the heya will receive in these next rankings. So, theoretically, it takes care of itself.
Additionally, if you follow the above logic, it stands to reason that a rikishi competing at the top end of Juryo and achieving kachi-koshi and on the cusp of promotion (2+3 points) is fighting at a similar level to a rikishi at the bottom end of Maegashira rank who gets a make-koshi and is in danger of demotion (5+0).
Here’s where we will create variance from month to month, with points being awarded for the following achievements:
Yusho (Makuuchi): 50
Jun-Yusho (Makuuchi): 25
Makuuchi Special Prizes: 10
Yusho (Juryo): 15
At the end of the day it’s really all about winning the big prizes, and these represent prestige. These are the people who have been the focal point of the two weeks that have passed, either because they have outperformed their level, they have challenged for the yusho, actually won it, won a big promotion up to the next level, or all of the above.
Haru-basho Power Rankings & Analysis
What we’ve got above is a bar chart of January’s ranks vs. March, so that we can see for this first edition which stable is at the summit of the sport, who’s improved their standing, and also how the Haru basho might have negatively impacted stables. Here’s our inaugural top 20 chart, with their score in brackets:
The headliner for the second consecutive basho is the Tagonoura-beya, headlined by Shin-Yokozuna Kisenosato‘s heroic yusho, and another prize-winning outing by san’yaku fixture Takayasu. Perhaps unsurprisingly, the dominant Isegahama is not far behind, off the back of several prominent rikishi towards the top end of the banzuke and a just-nearly performance by Terunofuji. We can probably expect to see these two stables in or near the top two for some time to come, especially if Takayasu is successful in his Ozeki run.
Taking the bronze medal this time, it’s Sakaigawa: a stable with a number of makuuchi wrestlers and featuring the Juryo yusho winner Toyohibiki, who we’ll see back in the top flight for Natsu. While it’s not impossible, Sakaigawa will have a challenge to hold onto a position in the top 3 in May. Goeido will need to chase a kachi-koshi to retain his Ozeki status, but they may lose 2 rikishi from makuuchi to Juryo with demotions, and the next best heya Miyagino will hope for a healthier outing from Hakuho and better returns from Ishiura as he tries to cement his place in makuuchi.
Looking at whose stock plummeted the most this month, you can’t look further than the first name on the list. With only one rikishi in the top 2 divisions, Arashio‘s prestige is wholly dependent at the moment on the performances of Sokokurai, whose gino-sho winning Hatsu was followed up with an 11 loss outing this time around. Solid but unspectacularly performing heya with a diversity of competitors (e.g. Kokonoe) are better able to insulate themselves from this kind of performance, and Arashio doesn’t have anyone else near the top divisions at the moment.
On the whole, this exercise has shown that out of all of the places that rikishi live and train, about a dozen are real players at the top end of the game, and another dozen are developing middling talent trying to gain a foothold in the professional ranks. The rest are in limbo, either unable to produce top level talent at the moment or simply in a transitional period where their top level participants have recently retired or been demoted while they try and bring through a new generation of rikishi with the ability to compete at the highest level.
Looking ahead to Natsu, I don’t think we should expect much change in the top 5. A few stables under the radar who might make moves one way or the other in the near future:
Oitekaze: Endo will move up, and may face a tougher schedule given that many of the rikishi in front of him this time out are staring at demotion. Meanwhile, Daieisho‘s due a promotion and Oitekaze’s quintet could be joined soon in the professional ranks by Iwasaki, who picked up a kachi-koshi at Makushita 3, and Daishoho, who made his brief Juryo debut in November and just put up 5 wins at Makushita 7.
Takanohana: As Andy noted earlier in the week, Takagenji is set for his Juryo debut at Natsu, and while Takanohana isn’t teeming with the sheer volume of rikishi that you might see at other stables, there are actually a couple more young wrestlers not far behind. Star man Takanoiwa‘s results have been volatile, but he has made a step forward in the past year which is that he’s now more able to cope with what the schedule throws at him at the lower end of makuuchi. Likewise, Takakeisho seems to be settling in well as a rank-and-filer and will move up the banzuke next time out.
Sadogatake: It’s tough to call a heya with such a rich history at the top level “under the radar,” but they’ll take a hit if Kotoshogiku does retire or show diminished performance following a soul-crushing nearly-basho in March, and it would be charitable to say that Kotoyuki hasn’t been at his best recently. He looked overpowered and out of sorts more often than not at Haru. Realistically the next wave of talent here is at least a couple of years away – there are a handful of journeyman rikishi at Makushita level already, but the next youngster showing serious promise looks to be 19 year old Kotokamatani who just finished up a 5 win basho at Sandanme 3 and is primed for already his second spell at Makushita having only made his tournament debut last January.
Hi there – this is my first guest post on the site, so thanks for having me! Following Bruce’s analysis last week, contrasting the early upper san’yaku vs lower san’yaku results from the current Basho to that of last year’s Nagoya tournament, I posited that it might be interesting to have a look at a larger sample size and determine if what we’re seeing is the product of a shift in the performance of the upper san’yaku over time, and what it might mean.
I pulled the first week win/loss data (up through day 8) of each tournament going back to January 2015, the logic being that a 2 year period of first week bouts would give us an idea of what it means to perform at the level of a Yokozuna or an Ozeki in this day and age. I selected 8 days because this has typically been the tipping point in the tournament after which the upper san’yaku (of which there have usually been 7) stop being polite and start being real, and are then starting to fight each other.
Finally, I removed forfeit matches due to rikishi going kyujo from the equation entirely. While these wins and losses show up in the history books, they don’t give us a true read on whether or not the rikishi involved are performing at the expected talent level.
This is all basic stuff and is meant to be a jumping off point from which assumptions can be based so that we can have some more detailed conversations in future. So let’s see what the data (which you can see in rawer form here) tells us:
* A Yokozuna can usually be counted on to lose one match in the first week. Over 2015 & 2016, the win rate (or wins per day in Bruce’s format) of a Yokozuna is 85.7%. Taking into account that healthy rikishi will fight 24 times, we’d expect to see 3 losses from the group and this is exactly what happened in 8 of those 12 tournaments.
* Ozeki typically perform 15% worse than the Yokozuna. So, they lose a little more than 1 more match apiece on average than their more prestigious counterparts. Interestingly, this is exactly what has transpired in 2017 as well as 2015 and 2016 – the downturn in Yokozuna performance (~10%) has been almost exactly matched by their Ozeki counterparts in spite of Kisenosato moving up a level: his brilliant Hatsu masked disasters from Terunofuji and Kotoshogiku, while his promotion has covered for the kyujo Hakuho and underperforming Harumafuji and Kakuryu.
* Hakuho isn’t in trouble – at least as far as week 1 is concerned. He was 7-1 in January and having gone kyujo twice in the 2 years prior (including once mid-basho), he came back with 8-0 and 7-1 starts. He clearly was struggling early in this tournament along with Harumafuji and Kakuryu (who have since seen their records improve), but if his body works then the early results bear out when fighting against his lower ranking san’yaku competitors.
* Sekiwake up their game. Over 2015-16, the expected win rate for a Sekiwake in week 1 was a paltry 46.3% – you wouldn’t even expect them to end up 4-4 never mind challenge for Ozeki promotion, which obviously only happened once (Terunofuji) in that time frame. However this has increased over the first two basho of 2017 to 64.6% – almost as good as an Ozeki would usually be expected to perform (70%).
* This hasn’t been reflected at Komusubi level. Usually Komusubi win 33.2% of their first week matches, but that’s only up to 35.4% this year. Tochinoshin’s tanking at Hatsu is somewhat to blame for this but of the four Komusubi performances this year, only Takayasu has turned in a winning performance at the level in matches fought, and even that was only a 4-3 standing after 8 days. This is still as hard of a level as ever to compete at.
* The recent lower san’yaku level of performance isn’t totally unprecedented, however. While we began to see the tide swing toward the lower san’yaku in January, there were actually 5 better performances over the past couple years – a 5 basho streak starting with a 50% success rate in March 2015 through to a 43.8% hit rate in December 2015 – from the up and comers than in January (42.9% success rate).
* Takayasu may be more special than we think. Most Sekiwake have never returned to the rank over the past 2+ years: only 3 prior rikishi have re-obtained the title after losing it since the start of 2015. However, unlike Ichinojo, Myogiryu and Okinoumi, Takayasu looks to be the first to fight back and look capable of not only hold the rank but have the stuff to move up. Of the prior three, only Myogiryu was even tenuously able to cling on for one more basho at the ranking.
* Kisenosato starts as well as anyone not named Hakuho. While his historical troubles with finishing off the yusho have been well detailed, his week 1 performances have outshined Kakuryu over the last 2+ years and he’s in a dead heat with Harumafuji’s level of performance. While it’s not clear yet that he’s better at this level than a healthy Hakuho, Hakuho’s toe problem means the Shin-Yokozuna was already for all intents and purposes the top dog coming out of the traps even before the the first grain of salt was thrown at Haru.
* No one’s success rate has taken a bigger hit than Goeido. The Ozeki from Osaka’s first week win rate has dropped over 20% in 2017. Historically he’d been expected to win almost exactly two thirds of his opening week matches, but he now sits at a lacklustre 46% – the exact tally we’d typically expect from a Sekiwake that’s might be demoted lower. He really shouldn’t have turned up unfit at Haru.
So what does all of this mean? There’s a certain shift as we’re seeing results that haven’t been there over the past several years, but it’s much too soon to call it a day on the current crop of Yokozuna. At Haru, they’ve lost 2 more matches as a group than we’d expect to have seen, but as recently as November they were turning in a vintage week 1 performance that stands up to anything else they’ve done recently, battering the lower san’yaku with better than expected results.
Health aside, in the short term the data shows that we can probably expect to see some more turbulence in the rankings of a small group of rikishi in between the Sekiwake and Ozeki tiers, and what it means to fight at those levels may become somewhat blurry if Kotoshogiku ends up as the first in what could be a string of yo-yo rikishi. The next two or three basho will be telling to be sure, and I’ll continue to update the data to see how the san’yaku bear out against each other in the early going to try and pick up more signals.