Geoffrey Boycott

 was a cricket player. The Fifth Doctor and Peri once attempted, and failed, to attend a match where he score his hundredth hundred, which the Doctor claimed was an important event in English sports history. (PROSE: Light at the End of the Tunnel)

Behind the scenes
Neither Light at the End of the Tunnel nor Graham Dilley Saves the World specifies the first name of Geoffrey, but the clear intent of both stories is that the reader is meant to infer it.