Cunis was an unusual kind of bowler. He had a very complex bowling action which made him look like a wrong-footed bowler. And was also a handy lower-order batsman. Started his domestic career with Auckland in 1960 and ended it with Northern Districts in 1977. In between, he managed to scalp 386 first class wickets at 26.65 including 18 5-fers and two 10-wicket hauls.

John Arlott, BBC commentator and journalist described Cunis as "neither one thing nor another." That is because in his 20 Tests for New Zealand, he took 51 wickets with only one 5-fer and scored 295 runs with a highest of 51. However, at his peak he was selected to play for the World XI against Australia along with Sunil Gavaskar, Clive Llyod, Zaheer Abbas and Gary Sobers.

The highlight of his career was when he played the innings of his life for New Zealand in the second innings of the third Test against Pakistan in 1969. He added 96 runs for the seventh wicket with Mark Burgess that enabled Black Caps to draw the game and win their first series on foreign soil.

Also a more than capable rugby player, Cunis played as three-quarter. He passed away on August 9, 2008.