Sumo Elo History for the Aki Basho
Sumo wrestling has a long and colourful history in Japan, and records for tournaments stretch back decades. Elo rating systems (familiar to chess fans) can be use to compare the bout-by-bout performance of wrestlers over the entire history of their time in the sport.
Using data from sumodb reference site I computed Elo ratings for every sumo in the Makuuchi division from 1990 onwards. That’s a total of 97632 sumo bouts involving 262 wrestlers. Below are some Elo history highlights for the stories on the Tachiai blog with an eye to the Aiki basho next week.
The Current Yokozuna
Below is the full Elo history for Yokozuna ranked wrestlers present competing in the forthcoming Aki basho in Tokyo next week.

Hakuho considered by many to be the greatest wrestler in modern sumo history (and perhaps ever) clearly shines in his prime at the turn of the last decade. With him approaching his 65th tournament as Yokozuna has perhaps started to move past his peak. Two missed tournaments due to injuries in the past year have somewhat eroded confidence his ranking.
After a disappointing year in 2017, Kakuryu has made an excellent comeback this year with convincing performances in the first three basho’s of 2018. In terms of Elo, he looks like he’s currently the strongest Yokozuna (or at least the least injured). However, with a knee injury on day six of the Nagoya basho it will be interesting to see if he has recovered full in time for the Aki tournament.
Kisenosato on the other hand looks to be on increasingly on the verge of retirement. He hasn’t competed in a tournament since the Hatsu basho at the beginning of the year, and prior to that had to decline to enter or pull out of the previous 5 tournaments before that devastating his Elo score by over 100 points. After 3 tournaments off to recover, the Aki basho is likely his last chance for being encouraged to retire.
Tochinoshin the Troubled Ozeki

Tochinoshin suffered as ligament injury in 2013 and fell from the Maegashira ranks to the Makushita division. He returned to the ranks of the Makuuchi in late 2014. He had further trouble in early 2017 with a knee injury leading to some loosing streaks in tournaments throughout the year. After an awesome 14–1 win (beating both Ozekis, both Sekiwake, and a Komusubi) launching his Elo score through the roof at the beginning of the year and another strong 13–2 showing in July he was promoted to the ranks of the Ozeki.
However, after dropping out of the July tournament with a toe injury he was marked as kadoban requiring him to get at least 8 wins in Aki to retain his place in the Ozeki, meaning he has it all to play for over the next two weeks.
Mitakeumi the Up & Coming.

Mitakeumi has held the rank of Sekiwake for 6 tournaments out of the last 7. After a dip in his performance in March back to Komusubi he has had a good performance in the last two tournament to catapulting him over 75 Elo points and giving him a chance for Ozeki in the Aki basho.
However, with many of the leading figures absent due to injury in the July tournament, and with all Yokozuna & Tochinoshin returning the chance for him to make the leap to the ranks of Ozeki is likely to be a difficult road.