And for Fergie, it has all to do with the local canals.
"What's his name, who built the ship canal? Mason? No it wasnae Mason," began the Scot.
Daniel Adamson was the engineer behind the construction of the canal.
"He took all the industry away from Liverpool to Manchester. From that day on, the rivalry between the cities was there. Therefore, it's not just football; geographically, there is fantastic competition.
"Of course, being the two most successful clubs, that has intensified over the years and that won't change. 'If we two were bottom of the league or in the second division it would be the same."