A fast bowler, McGregor Billing made his first-class debut in 1920–21 at the age of 33.
In the final match of that Currie Cup season, when Natal needed to beat Western Province to win the title, Billing took 6 for 42 (five bowled) to dismiss Western Province in their second innings for 134 and leave a target of 227 for Natal to win, but they were dismissed for 199.
[1] In 1921-22 the same teams again met in the final match of the Currie Cup; this time Billing took 2 for 52 and 5 for 37 to help Natal to victory and a shared title with Western Province and Transvaal.
[3] Billing took five wickets for Natal against S. B. Joel's English team in 1924–25, and was later selected for South Africa in the first of the five unofficial Tests.
He took the wicket of the opener Jack MacBryan cheaply in each innings, and made his highest first-class score of 32, and South Africa won, but he did not play any further matches in the series.