Commenting on my post about Ozeki runs, SMB asks:
I assume that the people deciding on Ozeki promotions are aiming to promote rikishi who are likely to make long-term Ozeki and potential Yokozuna. You included some examples of the outcomes of Ozeki promotions, but it would be interesting to see more analysis of how successful the Ozeki promotion decisions have turned out to be. In other words, do the decision makers largely get it right, if they are aiming for long-term Ozeki?https://tachiai.org/2019/02/14/a-brief-history-of-ozeki-runs/#comment-15017
This is a great question. Of course, what counts as a long-term or successful Ozeki is necessarily somewhat subjective, but we can look at the history to get an idea. As usual, I will limit the analysis to the six annual basho era from 1958 to the present. Sixty rikishi were promoted to Ozeki during this time. How have they fared?
Reaching The Top
A clear career goal for Ozeki is making it to Yokozuna, sumo’s highest rank. Of the 60 most recent Ozeki, 26 have made this final ascent. Five who have not are still active, although the chances that Kotoshogiku and Terunofuji regain the rank of Ozeki, much less become Yokozuna, seem exceedingly remote, and I would put the likely expected number of promotions from among Goeido, Takayasu, and Tochinoshin at one. In any case, the odds that an Ozeki takes the next step are close to 50:50.
While it could be argued that making Yokozuna always counts as success, there is one obvious exception: Kitao. He became the 60th Yokozuna, under the shikona Futahaguro, after only four basho as Ozeki and despite not winning a yusho. He failed to do so in his eight more tournaments at the top rank as well, becoming the only Yokozuna not to win a championship, and was forced to leave sumo in disgrace.
Many of the most successful Yokozuna have treated the second-highest rank as a brief waypoint on the climb to the top. The nine Ozeki not named Kitao who spent between 3 and 7 basho at the rank have 191 yusho among them, and seven of them are all-time great Dai-Yokozuna: Taiho, Wajima, Kitanoumi, Chiyonofuji, Akebono, Asashoryu and Hakuho. Of the three other modern Yokozuna with double-digit championships, Takanohana had to wait 11 tournaments (with 5 yusho!) for promotion, Kitanofuji took 21, and Musashimaru is tied for the most tournaments at Ozeki before Yokozuna promotion with 32, as well as the most Ozeki yusho with 5. The average number of basho at Ozeki before promotion is 13.5, or a little over two years.
Interestingly, in light of the oft-discussed “two consecutive yusho or equivalent” guideline for Yokozuna promotion, fully half of the 26 promotions happened with either zero (Kitao and Mienoumi) or one yusho as Ozeki, and only 11 followed consecutive championships. For more on the rather fluid and ever-changing criteria for Yokozuna status, I highly recommend this terrific video by Chris Gould:
You can skip to the part about modern promotion guidelines at 8m 15s, but the whole thing is well worth a watch.
The Terminal Ozeki
What of the 29 (retired) rikishi for whom sumo’s second-highest rank represented the pinnacle of their career? They range from Daiju, who lasted 5 undistinguished basho at the rank in 1973-74, to Kaio, who set the standard for Ozeki longevity and excellence with 65 basho (tied for the most with Chiyotaikai) and 4 yusho, the most among Ozeki who did not become Yokozuna. On average, an Ozeki career has spanned just over 27 basho, or 4.5 years. The time spent at the rank drops to around 21 basho, or 3.5 years, if we include those who vacate it through Yokozuna promotion. Given that there have been 60 Ozeki promotions in just over 60 years, 3.5 also represents the expected number of Ozeki on the banzuke at any one time, so we are a tad below average with three at the moment.
How many of the 29 can we regard as “successful”? Six lasted 12 basho or fewer at the rank, with zero yusho. These are pretty clearly misses, for one reason or another. On the other end of the distribution, there are eight “super-Ozeki” who held the rank for 36 or more basho and won at least one yusho. In addition to the aforementioned Kaio and Chiyotaikai, this group includes such notables as Takanohana I, the father of two future Yokozuna, Konishiki, the first foreign Ozeki, and Kotooshu, the first European to raise the Emperor’s Cup. The other 15 can be regarded as average Ozeki, serving between 2 and 6 years and often picking up a yusho along the way (Wakashimazu managed 2 yusho, and Tochiazuma won 3). So, if we regard these as “successful”, then the decision makers “get it right” almost 90% of the time; if we raise the bar to either lasting longer than average at the rank or being promoted to Yokozuna, this rate drops to a little over 70%.
Does The Quality Of The Ozeki Run Matter?
As noted in my previous post, 18 of the 60 Ozeki reached this rank after recording fewer than 33 victories in the 3 basho before promotion, 14 recorded exactly 33, and 28 recorded more. The average is just over 33 wins. We can ask if the number of wins during the Ozeki run correlates with subsequent success at the rank.
How do we measure success? We can try a couple of ways. First, does the number of wins predict which Ozeki go on to make Yokozuna? The answer is “no”—the correlation is actually slightly negative, with 33 wins for those who eventually make the next level, and 33.4 for those who do not. Ten of the 18 rikishi promoted with fewer than 33 wins reached the highest rank. Next, we can look at the length of the Ozeki career among those top out at the rank. Here, there is a weak positive correlation (0.18) with the number of wins, but it’s not statistically significant.
Interestingly, the one metric that does show a moderate correlation (0.39) with the number of wins during the Ozeki run is career yusho won by those who make Yokozuna. Only two of the 10 Dai-Yokozuna were promoted to Ozeki with fewer than 33 wins, while six recorded more than the target number. The future greats usually have no trouble racking up wins on their way to Ozeki promotion, just like they tend to pass through the rank quickly.
How Do The Active Ozeki Stack Up?
With the historical numbers in hand, I’ll close with a brief look at the active Ozeki (or former Ozeki). Assuming that Kotoshogiku’s Ozeki days are behind him, his 32 basho and 1 yusho would place him somewhat above average among those who never made Yokozuna. Were his career to end today, Goeido, with 27 basho at the rank and one yusho, would already grade out as pretty much exactly an average terminal Ozeki, and of course he will continue to accrue service time, so the scorn often heaped on him is undeserved. With his 14 basho as Ozeki, the sad tale that is Terunofuji falls just outside the bottom six. And we can all hope that the stories of the Ozeki careers of Tochinoshin and Takayasu are far from finished.