From The Doctor and the Detective - A Biography of Sir Arthur Conan Doyle by Martin Booth:

“Being of muscular build, he also did well at swimming, football, hockey and ice-skating. He additionally played rugby (to unique Stonyhurst rules), was fond of fishing in the nearby rivers Ribble and Hodder and, towards the end of his school life, took to billiards. Rugby he later considered the best of all team sports because it required stamina, agility, bravery and ingenuity simultaneously and, in later life, he denounced public schools that played the game according to individual sets of rules because this lessened the ability for boys to play universally.”