I’ve got a new book about sumo, specifically sumo terms in Japanese, and I’ve been loving it. One new term for me is “Aikuchi ga warui” (or, conversely, Aikuchi ga ii). In Japanese it looks like this: 合い口が悪い. The term is used for a difficult opponent, one whom at your level you should be able to beat more frequently but you just can’t do it. In English, I think I’d equate it to someone who’s “got my number.” As an example, Kotoeko appears to have Wakatakakage’s number, as we can see in these tweets below:

Their rivalry is pretty young, having faced each other 7 times with Kotoeko winning 5 of their bouts. When I started drafting this article a few months ago, Wakatakakage was down 5-to-1. Wakatakakage actually claimed victory this July. And wouldn’t you know it, he also beat the other example I was going to use, Mitakeumi. Until July, he had gone 0-4. Even with this terrible July, he somehow figured out a way to beat Mitakeumi and Kotoeko, two rikishi he’d had difficulty with previously.

So, what’s another example? Let’s take a look at Shodai. He has beaten Takarafuji 14 times in 17 bouts. But Kaisei, of all people, has his number. Shodai has never beaten Kaisei, not counting fusen. The first visualization that I’m releasing here is the heatmap. The size of the box indicates the number of bouts they’ve faced each other, with the most going from top-left to the least at the bottom right, with a minimum of three bouts. That minimum kicks out a lot of the young guns and low rankers. More red means a worse win/loss ratio (aikuchi warui). Darker blue means a better ratio (aikuchi ga ii). I’m still working on ways to visualize trend or other “rivalry” metrics to see who’s been winning lately, that kind of thing. To prevent having this load every time someone visits the site, continue reading below to see…