[2] His father, John MacCormick, was a barrister who worked in Auckland,[a][5] but both Arthur and his older brother Charles were born in Australia.
[7] MacCormick worked for the Colonial Bank of New Zealand, initially in Auckland before transferring to Dunedin in March 1888.
[8] He had been considered for selection for an Auckland side against a touring Australian team in 1886, but was unable to get leave to play.
The New Zealand Herald described him as a change bowler who "bowls pretty well" and who "is a fair batsman" despite being "very nervous" at the crease.
[7] His only first-class match was a January 1889 fixture between Otago and Canterbury played at Lancaster Park in Christchurch.