Keep banzuke side separate from the left or right position used on a daily result screen. Extract division, rank, numbered slot and east/west designation from the official banzuke, then join results by wrestler and tournament. Compare similarly ranked groups before describing the full east side against the full west side.
The official banzuke displays east and west positions within ranks and numbered slots; daily results and the scorecard display bouts and outcomes. Those pages do not say that being placed east changes a win rate. Any observed gap still has to be separated from rank composition, opponents, absences and period. East and west are not personality types or geographic biographies.
Use one wrestler-tournament row
Store tournament, division, rank, number, banzuke side, wrestler identifier, wins, losses, absences and defaults. The side comes from that tournament’s ranking, not from where a name happens to appear in a bout table. Record unpaired positions when a rank has an odd number of wrestlers or a roster structure does not produce a neat east-west pair.
Before calculating a makuuchi-wide average, inspect rank and absence distributions. We infer that same-number matching and rank stratification can reduce some composition bias, but they do not prove a causal side effect. If an adjusted estimate disappears or reverses sign against the unadjusted total, retain that counterevidence instead of choosing the friendlier number.
A bout is not a simple east-versus-west experiment
Schedules cross ranks and do not turn the whole tournament into a randomized side trial. Preserve opponent rank, day and default status. Report contested bouts separately from official decisions if defaults matter. Never explain an individual result with the banzuke side alone.
Across several tournaments, the same wrestler may move between east and west. A within-wrestler comparison can reduce some differences between people, although changing opponents and rank still remain. State those limits rather than promising that one adjusted number proves a side advantage.
Never turn missing side into west
An unpaired rank, blank field, name change or partly populated display does not explain itself. Do not code every unresolved row as west or invent its missing partner. Publish the count and reason status in a separate exception table.
If the join or denominator cannot be reproduced, the safe fallback is a descriptive count plus the unresolved total—not an east-side verdict. When defensible adjustments disagree, show each result and hold the conclusion.
Enjoy the movement on the page
Following east and west reveals a small paper trail: the same shikona shifts across the banzuke as results accumulate. On the next ranking, look beyond whether a favourite moved up or down and notice whether the side changed. It is not a verdict on character. It is one more trace of how the previous tournament was translated onto the page.
Counterevidence and the Update Trigger
The result is limited to the stated period, population and missing-data treatment. An official correction, a newly completed tournament, a changed exclusion rule or a failed recalculation is an update trigger. Preserve the previous value, reason for change and recalculation date; do not strengthen a conclusion using only convenient new records.
Sources
- Japan Sumo Association, banzuke table, daily bouts/results, and tournament scorecard (checked 4 September 2026; source fields retain their scope, while joins and missing-data rules are our analysis).
Source links used for verification
Each link was used for the corresponding claim in this article; inclusion is not a blanket endorsement of the whole page.
Article verified:
- Japan Sumo Association banzuke tablePrimary source (as checked for this article)
- Japan Sumo Association daily bouts and resultsPrimary source (as checked for this article)
- Japan Sumo Association tournament scorecardPrimary source (as checked for this article)