Career
At club level Gronow played under the union code for Bridgend Reconstruction Finance Corporation, county rugby for Glamorgan and international rugby for Wales union team He was often used as a utility forward. When he switched to professional league rugby he represented Huddersfield (twice), Grenfell, Batley, and Featherstone Rovers, while at representative level, Gronow played for Great Britain, and Wales.
His playing position varied under the league code being used as a prop, second-row, and loose forward/lock, id est (that is) number 8 or 10, 11 or 12, or 13, during the era of contested scrums.
Gronow was also capped for the Great Britain rugby league team while at Huddersfield, in 1911 against Australia (2 matches), and after being selected for the 1920 Great Britain Lions tour of Australasia, against Australia (2 matches), and New Zealand (3 matches). Ben Gronow played Left-prop, id est (that is) number 8 in Huddersfield"s 2–8 defeat by Wakefield Trinity in the 1910 Yorkshire Cup final during the 1910-1911 season at Headingley Stadium, Leeds on Saturday 3 December 1910, played Right-prop, id est (that is) number 10, and scored 4-conversions in the 18–8 victory over Dewsbury in the 1919 Yorkshire Cup final during the 1918-1919 season at Headingley Stadium, Leeds on Saturday 17 May 1919, played Right-prop and scored 3-conversions in the 24–5 victory over Leeds in the 1919 Yorkshire Cup final during the 1919-1920 season at Thrum Hall, Halifax on Saturday 29 November 1919, and played Left-prop and scored a conversion in the 4–10 defeat by Hull in the 1923 Yorkshire Cup final during the 1923-1924 season at Headingley Stadium, Leeds on Saturday 24 November 1923.
Gronow also played at least one game for the Other Nationalities team, on 5 February 1921 against England. The game was notable for the Other Nationalities side being entirely composed of Welsh players.
But despite approaches to have the game recognised as a "Wales" v England encounter the rugby league authorities refused to accept the request.
Gronow beame one of less than twenty-five Welshmen to have scored more than 1000-points in their rugby league career. Gronow was selected for Great Britain while at Huddersfield for the 1924 Great Britain Lions tour of Australia and New Zealand, he did not play in any of the Test matches on this tour. In 1925 Gronow became the first British player to move down under when he went from Huddersfield to Grenfell, New South Wales as their coach but returned two years later.
Gronow was the coach for rugby union team Morley R.F.C. in the 1930s, however when a history of the club was produced some years later, due to his previous rugby league associations, he was identified as "unknown" in a team photograph.