Whyld was a strong amateur chess player, taking part in the British Championship in 1956 and winning the county championship of Nottinghamshire. He subsequently made his living in information technology while writing books on chess and researching its history.
As well as the Oxford Companion to Chess, Whyld was the author of other reference works such as Chess: The Records (1986), an adjunct to the Guinness Book of Records and the comprehensive The Collected Games of Emanuel Lasker (1998). He also researched more esoteric subjects, resulting in works such as Alekhine Nazi Articles (2002) on articles in favour of the Nazi Party supposedly written by world chess champion Alexander Alekhine, and the bibliographies Fake Chess Automata in Chess (1994) and Chess Columns: A List (2002).
From 1978 until his death in 2003, Whyld wrote the "Notes and Queries" column in the British Chess Magazine.
Shortly after Whyld's death, the Ken Whyld Association was established with the aim of compiling a comprehensive chess bibliography in database form and promoting chess history.