[2] Houlihan turned professional in 1971 at the age of 42 after many years as an amateur including beating future world champion John Spencer 11–3 at Blackpool Tower during the 1965 English Amateur Championship final.

In 1966, Spencer, who by then had won the 1966 English Amateur title, rather than Houlihan, was the representative at the rescheduled IBSF tournament.

In the meantime, Houlihan had been imprisoned for four months for his involvement in the burglary of a warehouse.

[3] His move to becoming a professional had been stymied by world champion turned snooker star, Joe Davis, who was responsible for selecting new professionals and disapproved of amateurs such as Houlihan who had played matches at various snooker clubs for money.

[3] During his professional career his highest position in the world rankings was 18th, which he reached in 1979.