A right-arm fast bowler and hard-hitting lower order batsman, Motz played 32 Test matches for the New Zealand national cricket team between 1961 and 1969.

[3] He played domestic cricket for Canterbury, making his debut in the Plunket Shield in 1957, while still a schoolboy, taking 4 for 40 at his first outing.

[3][4] He made his reputation as a hostile fast bowler, and a big-hitting lower order batsman.

He took 8 wickets for 61 runs against Wellington in 1966–67,[5] and scored 103 not out against Otago in 1967–68,[6] making his only first-class century inside an hour.

[7] He took five wickets in an innings five times in Tests, once in England and twice at home against each of India and West Indies.

A monograph titled 'Working Man's Hero' written by Bill Francis was published in 2022.