He won the New Zealand Chess Championship six times between 1921 and 1940, and was the first player to win the title in three consecutive years.

[3][4] Dunlop undertook dental studies in London, and while there he learned to play chess, before returning to New Zealand in 1906,[5] and going into practice as a dentist in Dunedin.

[6][7] On 26 February 1912, Dunlop married Ailsa Vallange at St John's Church, in the Dunedin suburb of Roslyn.

Dunlop entered the 1914 national chess championship, but withdrew before the start of the tournament because of a family illness.

[9][11][13] He won the national championship the following year, and again in 1923, after a playoff, becoming the first person to win the title three times in a row.

[14] Dunlop played in the 1933 Australian Chess Championship in Sydney, but was on poor form and was never in contention for the title.