This instalment of the Guardian's long-running Knowledge column answers a reader's question about which footballer has made the biggest jump in competitive standard between two consecutive club matches, prompted by Malachi Fagan-Walcott's move from National League football to Champions League qualifying action within days. Readers respond with the story of Gary Plumley, a retired goalkeeper running a wine bar in 1987 who was hastily signed by Watford after an injury crisis and thrown into an FA Cup semi-final against Tottenham, which Watford lost 4-1.

Plumley, who had made almost 200 appearances for Newport County before drifting into semi-retirement with Welsh League side Ebbw Vale, was recruited partly because his father was Watford's chief executive; his only reward was an expenses cheque he used to buy a fridge. The column also covers other reader questions, including footballers who have donated rare antiques (such as Mousa Dembélé's donation of 18th-century treasures found during a hotel renovation in Antwerp) and examples of former players refereeing matches involving clubs they once played for, such as Sean Murdoch officiating a Scottish League Cup tie involving his old club Dunfermline.