[1] He began his football career at his hometown club US Tourquennoise in 1903, aged 17, and in October 1907, he was described by Ernest Weber, the star journalist of the French newspaper L'Auto (the forerunner of L'Équipe), described him as "playing in the first team for 4 years, featuring successively inside right", and even though he was carrying out his mandatory military service at the time, Dubly intended to play in the team each time he was on leave.

[7] Together with Albert Parsys, Henri Moigneu, and Gabriel Hanot, Dubly was a member of the UST team that won back-to-back USFSA Northern Championships in 1909 and 1910, thus qualifying the club to the USFSA French Championship,[1] winning the final of the 1910 edition on 1 May at the Parc des Princes, following a 7–2 win over SH de Marseille, a club made up of Swiss and English immigrants.

[8] In the following year, on 29 April 1911, Dubly started in the final of the Challenge International du Nord in Tourcoing, helping his side to a 2–1 win over the English club Cambridge Town.

[1] It was only because of Henri Bard's refusal to be selected (who was demanding money), that on 29 March 1914, the 27-year-old Dubly finally earned his first (and only) international cap for France in a friendly match against Italy in Turin, which ended in a 2–0 loss.

[1] Employed in a textile factory, Dubly was nonetheless president of US Tourquennoise, which had a brief professional adventure in the 1930s before returning to amateurism, and also a municipal councilor of Tourcoing.