Has there ever been a 15–3 in all competitions?

Never.

It would be a scorigami. Based on the average number of goals in all competitions, the chance of a game ending 15–3 is about 1 in 34,461,728,645.

Nearby scores

1. 16–2 Never
2. 16–3 Never
3. 16–4 Never
4. 15–2 Never
5. 15–3 Never
6. 15–4 Never
7. 14–2 Never
8. 14–3 Never
9. 14–4 Never