It was against Hartlepool in an FA Cup 3rd round tie. The player he nutted was called George Potter, who ended up in Withington Hospital. I think Dennis actually knew him from the North-East, and visited his bedside to apologise.
City won 6-0 / 3rd January 1976.
The blatantly obvious solution for the economic health of all clubs at this level, would be to go regional. More relatively localised rivalries surely means bigger crowds and larger away followings. The removal of overnight stays for clubs would be a godsend too. There would still be a way of...
