How this was made
A static site built from 129 records in a public repository. Every figure printed anywhere on it is computed at build time from those files and from four harvests, so a number on a page and a number in the API cannot drift apart.
The harvests. OpenStreetMap by Overpass, for 527 gyms, camps and stadiums in 58 countries. Wikidata, for 1186 people recorded as Thai boxers. Thai Wikipedia at a named revision, for the thirty technique names and the four regional lists. Wikimedia Commons, for 112 pictures, each with its author and licence printed beside it.
Tiers. Every claim carries one: cited names a source, harvested came out of an open dataset with its licence, tradition is general knowledge of the practice and is hedged, inference is this project's own reasoning from the above, and field means someone stood there. The record page for anything you doubt has the table at the bottom.
Both languages, or neither. Each page is one build function called twice. Where a record has no Thai text the Thai page says so and shows the English rather than machine-translating in silence. 266 fields are written in Thai.
What it does not have is on its own page, linked from the numbers.
Who made it. hongdam.net, a bilingual web studio in Chiang Rai. The enriched, graphical sites in this family are all built there.