About Pitchonomics
Pitchonomics maps the economy of professional football in Japan: who pays whom, on what terms, and under what rules. We establish what we can from public sources, hold it in a structured database with a source attached to every record, and write from that.
The publication is written in Japanese. This page is the English account of how the data is made and what it can be relied on for.
What we have collected so far
Sponsorship agreements involving J.League clubs — which company, which club, which asset, and over which period — together with the financial figures the clubs and the league disclose. All of it comes from publicly available information.
Other parts of that economy — broadcasting rights, transfers, ownership, the league's own distributions — are not in the database yet.
Every fact carries a source and a date it was checked
We grade sources in three bands:
- A — the party itself. An announcement or an official page from the club or the company.
- B — the league, or established news media.
- C — everything else. Secondary aggregators, and visual confirmation of a shirt or a board.
A record resting on C alone is not published as established fact. Secondary sources get things wrong in ways that matter here: the brand on the shirt and the legal entity that signed the agreement are not always the same company. Visual confirmation tells us where a sponsor appears. It is never evidence that an agreement exists.
We keep track of what the parties themselves have confirmed
For every record we hold whether it has been verified against an announcement by one of the parties to the agreement, or rests only on reporting that the parties have not confirmed. A record of the second kind is raised to the first as soon as a primary source appears. What we put in front of a reader is the source itself: its name, a link to it, and the date we checked it.
Everything is stated as of a point in time
Agreements begin, change and end. We keep records as history instead of overwriting them, so a past season can be reproduced as it stood at the time. That is how the season selector on our data pages works.
We keep facts and estimates apart
Where an amount has not been disclosed, we say that it has not been disclosed. We do not publish estimated deal values as data, and we do not produce them on request. Where our coverage is incomplete, the gap stays visible: how much a club discloses is itself an observation about the Japanese game, and a plausible number written into that blank would destroy the observation.
An article may still carry an estimate, because some questions cannot be answered from disclosed figures alone. Where it does, the estimate sits in a section of its own, states its method, its inputs and its range, and is labelled a Pitchonomics estimate, so that it cannot be taken for a figure published by a club or by the league. Every input carries a source. If an official figure appears later we add what it turned out to be — including where we were wrong, and without deleting what we first wrote.
We compare only where the definitions line up
Accounting standards, the scope of disclosure and the way figures are aggregated differ between Japan and Europe, so setting the amounts side by side does not on its own compare the same thing. Where we use outside data for comparison, we first judge, indicator by indicator, whether the definitions are equivalent, approximate, or not comparable, and we publish that judgement along with the differences it rests on. Where the judgement is that they are not comparable, we do not compare them.
Figures we calculate, you can recalculate
Rankings, ratios, shares and year-on-year changes are worked out by us from disclosed figures. We state which items and which denominator went into each one, so that a reader holding the same public documents can arrive at the same number. If your recalculation disagrees with ours, the article is wrong, and we want to hear about it.
Corrections stay on the record
When a record or an article turns out to be wrong, we do not quietly change the value. The correction is published with its date and with what it changed, and the original wording is not deleted. A change in the agreement itself and a mistake of ours are kept apart in the history.
On English names and untranslated text
Where an English name for a company or a club appears on this site, treat it as a working form unless that party publishes its own English name. We have not yet verified, party by party, which of our English names are the parties' own. Until we have, the Japanese name is the authoritative one.
Two things stay in Japanese on purpose, including on English pages:
- The titles and publishers of our sources. These are the bibliographic details of the documents we read. Translated, they no longer lead back to the original.
- Category names as a club published them. A club's own wording for what a sponsorship covers is the fact we are recording. An English rendering of it would be ours, not theirs.
Contact
If you can point us to a primary source that corrects something we have published, please do.
Legal and further reading
These pages are published in Japanese only:
- 運営者情報 — Operator information
- プライバシーポリシー — Privacy policy
- メソドロジー — Methodology, a fuller account of how the data is collected, graded and corrected