Bonus Episode 3: Power Rankings

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As a fun little side project this winter, we put together possibly the geekiest thing we’ve done, and that’s including our fantasy sumo league. Using a variant of professional chess’s Elo ratings, we’ve created a power ranking system that we can update day-to-day to help quantify how well wrestlers are doing beyond just their record. Here’s a quick overview of how it works:


This first picture is a partial selection of our data entry system (for Kyushu 2017 to be precise). The axes are the list of rikishi in makuuchi and the chart shows which day they faced and who won. In Hakuho’s row, you see a ton of green numbers and 1 red, representing a bunch of wins and 1 loss. The number represents the day they fought and the sign (+/-) and color represent who won. With a little bit more programming this will be the only data entry we have to do and the rest will take care of itself.


This second picture is the first few days of our daily output. Within the column for each day you can see the opponent, the opponent’s ranking, the expected win chance, the change in points, and the wrestler’s new rating. For the most nerdy among you, here is our methodology. We started by assigning 1000 as a baseline value for an average wrestler. We arbitrarily assigned a starting rating based on the banzuke rating of every makuuchi rikishi in January 2017, from 1175 for yokozuna down to 825 for maegashira 16. Here are the formulas we used for the calculations:


This is how we calculated the expected win chance. We take the difference between our wrestler’s rating and his opponents’s and then use a constant, S, to calculate an expected win chance between 0 and 1. A lower value of S means the rating difference will have more effect on the expectation. For the first edition of our ratings, we used S = 200.


This formula takes the previous rating for our wrestler and adds a constant, K, times the difference between expectation and reality. The actual outcome is either 0 for a loss or 1 for a win and we compare that to the win chance previously calculated. K is effectively the max point swing. We are using K = 20 for now.


This last formula is how we regress to the mean between tournaments. We decided that everyone should be corrected 20% closer to our 1000 baseline. This corresponds to C = 0.8. By occasionally bringing everyone closer to our average value, we mitigate the effect of flukes and help nudge each rikishi’s ratings closer to a value that accurately represents their talent.

Here is a link to the full spreadsheet if you are interested. We plan to keep it updated as often as possible during each basho. Our next step is a more accessible way for everyone to follow along live. Let us know what you think or if you have any ideas for improvement!


Fantasy Sumo Results: Kyushu 2017

Better late than never, here are the results from our second basho of fantasy sumo. We had our first guest competitor and holy hell she destroyed us. Maybe we don’t need guests in the future… Anyway, here’s a quick overview of the scoring:

Each Match Won 1 pts
Each Match Lost 0 pts
Kachi-Koshi (8-7 or Better Record) 2 pts
Make-Koshi (7-8 or Worse Record) -2 pts
Yusho (Basho Winner Result) 5 pts
Jun-Yusho (Runner-Up Result) 3 pts
Each Kin-Boshi Awarded 2 pts
Each Special Prize Awarded 3 pts

Here’s a link┬áto the full spreadsheet if you want the details, but check out this massacre:

Team Score
Amy AH HATS 70
Ryan The Fat Five 48
Flyric MitaYoMamiNoShin 41
Mak KiT-KoT-Char 36
Jake The Brutal Bellies 29

Amy managed to get Hakuho and Hokutofuji thereby thoroughly embarrassing our whole crew. She was promptly kicked off the team to make space for a new guest in January. If you’d like to be that guest (and you aren’t as good as Amy at this), remember to submit a name for our mascot. We’ll pick our favorite and contact you through Twitter with the details on how to humiliate us at our own game.

Kyushu 2017 Recap

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From Harumaghazi to Onosho’s mawashi, Kyushu was a riveting basho. The GSB crew discuss the events and ramifications for the last tournament of the year. We have an ad from our sponsors at 34:29 and a special prediction series treat at 47:20. See if you can count how many ways we can mispronounce Aminishiki and enjoy the show!


Fantasy Sumo League: Kyushu 2017


Take 2 of Fantasy Sumo is underway and this basho looks to be a little easier on us for injuries. Will that stop us from blowing it anyway? Of course not. This round we welcome a new competitor: Amy, of Team AH HATS! She originally picked Takanoiwa before he pulled out for injury, but luckily Takarafuji was available as a replacement to keep the acronym intact. Teams are as follows:

Returning champ Flyric, of Team MitaYoMamiNoShin: Mitakeumi, Onosho, Chiyotairyu, Daiamami, Tochinoshin.

Newcomer Amy of Team AH HATS: Hakuho, Hokutofuji, Shodai, Takarafuji, Arawashi.

Seeking redemption after a tough Aki is Mak of Team KiT-KoT-Char: Kisenosato, Takakeisho, Kotoshogiku, Tochiozan, Chiyomaru.

Aki runner-up Ryan of The Fat Five: Harumafuji, Endo, Tamawashi, Takayasu, Ikioi.

And this basho’s future champ, of course, is Jake of The Brutal Bellies: Goeido, Yoshikaze, Asanoyama, Kaisei, Aoiyama.

You can check out our scores and scoring system on the link above and feel free to leave us comments and mockery.


Kyushu 2017 Basho Preview

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Kyushu is finally here and we still managed to screw it up! We recorded a day before yokozuna Kakuryu pulled out and we managed to make fools of ourselves predicting that he wouldn’t. We’ve got an ad at 42:32 and harsh ribbing throughout. Check it out and feel free to send us feedback!


Name me, and become our 5th fantasy sumo member next basho!


Fantasy Sumo Results: Aki 2017

Aki is complete, so it’s time to see who sucked the least at compiling a team of winning rikishi! A couple notes before crowning our winner:

  • Next time we will move this closer to the basho to avoid picking sumotori who pull out before the tournament even starts.
  • For November we will be adding a 5th player: one of you! Check out the final segment of our recap podcast for details.
  • Please feel free to give us feedback on our scoring. This is our first basho with this system so I’m sure there is plenty of tweaking we can do.

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