And as requested, here is how to calculate daily DoS. Basically, you look up the five bouts that your rikishi has fought against his opponent PREVIOUS to the current basho. Count the losses. If the rikishi lost all 5, the DoS is 5. If the rikishi lost 4, the DoS is 4, if the rikishi lost 3, then DoS is 3, if the rikishi lost 2, then the DoS is 2, if the rikishi lost 1, then the DoS is 1, and yes, you guessed it, if the rikishi lost 0, then the DoS is 0. The higher the number, the more difficult the bout is likely to be.
The calculation is based on the last five bouts because we want to get a sense of how the two are matched against each other that is more stable than looking at just one bout, but we don’t want to look at their entire bout history because if it stretches into the deep reaches of the past, it isn’t likely to predict the difficulty of their match now.
Finally, there are two possible problems to calculating DoS, if the rikishi and his opponent have faced each other less than five times, and if they have never faced each other before. Here is a link to the three possible ways to calculate DoS (normal, short bout history, first time to face each other).
Here is an example of the score sheet for Haru Basho Money shot. The three cases are to show you how to calculate the DoS (Difficulty of Schedule) score: The actual score sheet will only have three columns for you to fill in (Opponent Name, Daily DoS, and DoS Running Total).
This isn’t a perfect measure of Difficulty of Schedule by any means, but it is simple to calculate and it should provide a general indication of the Difficulty of Schedule for our rikishi.
The reason looking at Difficulty of Schedule is an important component of watching Sumo is that sometimes a rikishi has a terrible basho when they are ranked too high and fighing rikishi that are better than them, and then a really easy basho when they are demoted to a level that is too low and are fighting rikishi that are not as good as them. Because of these rank changes, it can often seem like a rikishi is doing really poorly one basho and really well the next, when in fact the level of their Sumo hasn’t changed – only the level of the opponents they are facing.
If you have any comments or questions about this system, feel free to share them in the comments section; I’ll be making the final score sheet over the next few days.