Ken was one of a rare breed of forwards with an ability to dominate games with sheer physical power and incredible ball-handling skills.

[3] Ken Roberts won caps for Great Britain whilst at Halifax, in 1963, against Australia where his début helped secure a 16–5 victory.

Combined Salford-Swinton – 1 appearance Ken Roberts played left-second-row in Swinton's 9–15 defeat by St. Helens in the 1960 Lancashire Cup Final during the 1960–61 season at Central Park, Wigan on Saturday 29 October 1960, played left-second-row in the 9–25 defeat by St. Helens in the 1961 Lancashire Cup Final during the 1961–62 season at Central Park, Wigan on Saturday 11 November 1961, and played left-prop in the 4–7 defeat by St. Helens in the 1962 Lancashire Cup Final during the 1962–63 season at Central Park, Wigan on Saturday 27 October 1962.

Ken Roberts played in Halifax's 15–7 victory over St. Helens in the 1964–65 Championship Final during the 1964–65 season at Station Road, Swinton on Saturday 22 May 1965.

The following season saw Halifax lose to St Helens in a repeat Championship Final at Swinton, and saw Ken make another incredible 36 appearances, including the fixture against New Zealand.

Ken would play a total of 39 matches for Bradford before making his début for a victorious Rochdale Hornets, against York, including a try, on 17 August 1968.