Two key criteria for developing good predictions are: (1) quantitative evaluation of the prediction and (2) accountability. With that in mind, I take a look at how my banzuke prediction performed.
Upper San’yaku was “chalk” as expected. In the lower San’yaku, I (and other predictions on this site) correctly had Yoshikaze filling the komusubi slot vacated by Shodai. I don’t understand the order of the three sekiwake ranks, as it appears unchanged despite the very different performances at Haru that had all of us predicting the order as Takayasu 1E, Kotoshogiku 1W and Tamawashi 2E.
In the maegashira ranks, of the 31 predictions, I had 11 “bulls-eyes” (correct rank and side” and 3 more correct rank predictions. This is way fewer than I expected or would have liked. The 17 misses were mostly not too bad: 13 missed by one rank, 3 missed by two ranks, and I had Osunaarashi (J1) moving up to M16 and Myogiryu (M15) dropping to J1.
There are three parts to the prediction: the computed ranks, tie-breaking among rikishi with identical ranks, and the departures I make from the computed ranks based on past banzuke patterns. Let’s look at these in turn.
The computed ranks were quite accurate: the official banzuke departs from these in only a couple of places. The computed rank would have Takarafuji at M3, but because of his make-koshi at that rank at Haru, the prediction and the banzuke moved him down to M4. Shodai (one of my two-rank misses) should be down at M7, and I still feel like the NSK cut him way too much slack after his 4-11 performance. And Arawashi and Ishiura would switch sides (but not ranks).
My tie-breaker was higher rank at Haru. This largely resulted in both of my other two-rank misses, as Takanoiwa should have been ranked above Tochiozan (and Aoiyama) by this rule. Presumably his 6-9 record at Haru led to his being dropped further down, although this is not necessarily consistent with past banzuke patterns. In a number of other cases, the tie-breaker got the relative order right, and I will need to look closely to see if the tie-break part of the prediction can be improved.
So, on to the departures from the computed rank order. One rule that resulted in many of my misses was to drop rikishi with 7-8 make-koshi records one spot from their rank at Haru, even if the computed rank would have them retaining their rank. This has often (but not always) been done in past banzuke. Although this rule correctly placed Takarafuji at M4, it placed Kagayaki, Tochinoshin, Ishiura and Daishomaru one slot too low, which also led to one-rank misses in the other direction for Ura, Arawashi, Kotoyuki and Onosho. It seems that the NSK is inconsistent in this scenario, and I’ll have to see if any pattern can be identified.
So overall, I am happy with my computed ranks, need to think more about the tie-break procedure, and need to be more careful with subjective departures from the computed ranks (this also includes demoting Myogiryu in favor of promoting Osunaarashi, even though Myogiryu had a better computed rank).
Others can chime in with how they fared. There will be another opportunity to predict the Nagoya banzuke after Natsu is the in books, and in the meantime we’ll have some actual sumo to watch!
