Duffy first gained an interest in gaelic games from his father (who was involved in the GAA locally) and attended his first All Ireland in 1958, where Dublin beat Derry to lift The Sam Maguire.
[9] One of the more controversial decisions of Duffy's tenure was the broadcasting deal the GAA signed with Sky Sports in 2014, which entailed a number of live senior All-Ireland Championship matches being exclusively aired on its satellite TV subscription service.
[12] Duffy also asserted that all commercialization decisions were taken to increase financial revenues for the GAA, the vast majority of which were then invested in coaching costs and capital expenditure on stadium infrastructure and local gaelic grounds.
[13] In another major change, Duffy was instrumental in introducing the "Black Card" to gaelic games in 2014 to help combat unsportsmanlike behaviour, where players deemed to be committing cynical minor fouls to prevent an opponent from performing would be sent off the pitch for 10 minutes, similar to the sin bin used in rugby.
[17] Duffy also helped to make significant changes to the manner in which quarter finals would be played from the 2018 All-Ireland Senior Football Championship onwards (informally known as the 'Super 8' system), where instead of the traditional knockout matches determining who would advance the teams would compete in a miniature round-robin tournament.
[18] Some of the notable events Duffy presided over during his 10-year stint included the International Rules Series in Croke Park, hosting Queen Elizabeth II during her 2011 state visit, and meeting with foreign dignitaries such as Barack Obama and Xi Jinping.