Club data checked against public sources, placed on a map and a timeline (external data lookup + hand-written). No trained model
Map: Natural Earth 1:50m coastline + 1:10m admin areas, transverse Mercator (central meridian −2°), converted to SVG at build time · 80 clubs, 23 derbies, 9 historic sites
England’s local authorities grouped into 47 ceremonial counties (Greater London included). Each ground’s county is found from its coordinates (one boundary case fixed by hand). Scotland, Wales and Northern Ireland use council areas
Derby distance: great-circle distance between the centres of the two grounds (Earth radius 6,371 km)
Trophies: lists of years won (top flight, national cup, league cup, major UEFA trophies); first major trophy and peak decade (the ten years with most trophies) are computed by code
League filter: 2026–27 leagues grouped as tiers 1–4 and 5+ (Scottish and Northern Irish top flights count as tier 1)
No training · runs in the browser · build: Node 22.23.4, d3-geo 3, topojson-client 3 · run 20261103T153816Z
LLM: Claude Opus 5.5 / written by AI: club descriptions and “roots” lines (Korean and English), fact-check searches / computed by code: what shows each year, counts by type, fact-check numbers, duel answers
■ Data
Founding years, stories, grounds and 2026–27 leagues: checked against Wikipedia club and stadium articles and club websites · retrieved 2026-10-25 · Wikipedia text CC BY-SA 4.0 (all sentences rewritten)
Ground coordinates: Wikipedia stadium articles. 16 positions without Wikipedia coordinates use other map sources (latlong.net, nonleaguegrounds.com etc.) or the address, and are marked approximate
First derby meetings: Wikipedia derby articles. Where an article contradicts itself (M23, Dundee), no year is shown
Positions of 57 town labels: approximate city centres (set by hand)
Trophy years: Wikipedia club Honours, List of seasons and 2025–26 competition articles. Years are season-end years. Community Shield, Super Cup and Intertoto excluded
Derby records and incidents: Wikipedia derby and incident articles (1971 Ibrox disaster, 2009 Upton Park riot etc.) and some news reports. Each record shows its as-of date; where a source contradicts itself, the page says so
Turning points: Wikipedia club and manager articles. One representative event per club; clubs without a clear trigger are marked Other
Type: public data + hand-written
Stored input: only your best duel streak, in this browser (localStorage). Nothing sent to a server, no personal data
■ Checks
Conditions: automated tests on the build output (Node + Playwright Chromium)
Club coordinates inside the UK bounding box: 80 / 80
Missing English strings: 0
Horizontal scroll at phone width: 375px 없음, 390px 없음
Clubs with disputed founding years are flagged on their card (Notts County, Crystal Palace, Sunderland, Kilmarnock and others)
Train/test split: not applicable
■ Scope
Clubs founded 1857–2004 · England 62, Scotland 11, Wales 4, Northern Ireland 3
All 20 clubs of the 2026–27 Premier League, many Championship and League One clubs, plus the oldest clubs and regional representatives. Not a complete list of UK clubs
Leagues as of the 2026–27 season (checked October 2026)