Settle the debate once and for all. Pick two English football clubs and we'll score it.
The "Is It A Derby?" score is based on a simple principle: what counts as "local" depends on the level you play at.
In the Premier League, clubs cluster in major cities — "local" means a few miles. But in the National League North, clubs are spread across vast regions. A 30-mile trip to your nearest rival genuinely is your local derby. Penalising lower-league clubs for geography would be unfair.
We calculate the straight-line distance between the two grounds, then compare it against a tier-adjusted derby radius. When two clubs are from different tiers, we average their radii — this stops a lower-league club getting an unfair advantage over a closer rival from a higher tier:
| Tier | Leagues | Derby Radius |
|---|---|---|
| 1–2 | Premier League, Championship | 25 miles |
| 3–4 | League One, League Two | 35 miles |
| 5–6 | National League, NL North/South | 50 miles |
The radius is then adjusted for club density. A club in London might have 15+ other clubs within 25 miles — so "local" means much closer there (radius shrinks to 40% of base). But a club in Norfolk might have only 1 or 2 neighbours, so they get a loneliness bonus — the radius widens up to 1.5× because they simply don't have other options. Norwich vs Ipswich at 40 miles isn't the same as Chelsea vs Brighton at 40 miles, because Norwich and Ipswich genuinely are each other's only meaningful rival. The loneliness bonus only applies when both clubs are isolated.
Distance score decays linearly: clubs at the radius score ~33, clubs at 1.5× the radius score 0. We then add bonuses:
| Bonus | Points |
|---|---|
| Same city/town | +15 |
| Same county (if different city) | +10 |
| Same league tier | +5 |
| Score | Verdict |
|---|---|
| 75–100 | Proper Local Derby |
| 55–74 | Local Derby |
| 35–54 | Regional Rivalry |
| 15–34 | Stretch — Barely a Derby |
| 0–14 | Not a Derby |