I'm so Scottish and only like Haddock and chips
I too love fish and chips
I think in England, Haddock is more commonly served as standard in the North, whereas the South seems to have Cod as the standard.
No idea why this is, but I lived in the North for many years before moving back to London, and got used to having haddock as standard (which I prefer; more and better flavour and texture I feel)