its known as the dockyard derby, as both cities claim to be the home of the Navy. Agreed its totally random to call it a derby in any sense however!
To be fair Plymouth probably would be better in the French league, they'll have less travel in a season.
Just looked it up, Portsmouth is Plymouth's 4th most local match after Exeter,Yeovil and Bristol Rovers.I guess anything under 200 miles is classed as a "Local game" to them
Portsmouth is about the same distance from Plymouth as it is from Leicester. Sent from my SM-G900F using Tapatalk