This is a fascinating insight into the vagaries of the football fixtures calendar.
Essentially, it's a massive Zebra Puzzle (incorporating the railways, the police, the FSF, bank holidays and horseracing amongst other things) and takes months to complete. For example:
"West Ham are paired with Dagenham and Redbridge. But for reasons of revenue, Southend request they do not play at home on the same day as the Hammers as they believe it impacts upon their attendance."However:
"Southend are in Essex, as are Colchester, so they cannot play together on the same weekend. Colchester share stewards with Ipswich so those two clubs also request they do not play home games on the same weekend. Transport links dictate Ipswich and Norwich do not play together on the same weekend either. In other words, when West Ham play at home can have an impact on when a club as far away as Norwich (108 miles) play their home fixtures."As I say, fascinating. Geek out.