Following the use of amateur sides as proving grounds for future professional players, the old boys clubs became isolated and broke away from the FA Amateur Cup to form the Arthur Dunn Cup in 1902–03. As of 2012, the club continues to enter the Arthur Dunn Cup, and reached the final during the competition's centenary in 2002–03, being defeated by Old Salopians. This was a replay of the very first title in 1903, when the Carthusians and Salopians shared the title after a drawn replay. By the time of the centenary, the Old Carthusians were the most successful team in the competition having won it on 19 occasions out of 24 finals reached and have since gone on to win it a further 5 times, making it 24 occasions out of 30 finals reached.