“TROY SCORES! Ten zero to Ireland!”
-- Ludo Bagman's commentary during the Bulgaria v Ireland final in 1994 (GF8)
Troy was a Chaser for Ireland’s National Team at the 1994 Quidditch World Cup.
During the final match of the 1994 Quidditch World Cup, Troy and fellow Irish Chasers Moran and Mullet were set to outscore Bulgaria, when Bulgarian Seeker Viktor Krum decided to catch the Snitch early and allow Ireland to win the tournament (GF8).
This Quidditch World Cup was overshadowed by the disturbing events that took place after the finish of the match (GF9, QWC).
Troy is a surname of French origin, from the city of Troyes in France (Internet Surname Database). Troy was also a city (in what is now the Anatolia area of modern Turkey) besieged by the Greeks, as set out in the "Iliad" of Homer (MIT Classics).
Like the other members of the Irish National Team, Troy is named for one of J.K. Rowling's friends:
"The Irish Quidditch team players are all named after people I have known. 'Moran', 'Troy' and 'Quigley,' are good friends. 'Troy' is one of my very oldest friends and she also happens to be a passionate supporter of West Ham Football Club. It is in her honour that the only soccer team ever mentioned in the books is West Ham." (JKR)
In the film, the character of Troy is played by a male actor, but it is not specified in the Harry Potter and the Goblet of Fire book whether Troy is a male or female.
Lexicon timeline of Quidditch
Lexicon list of Chasers
From the Web
Writing by J K Rowling on Imgur (Daily Prophet coverage of the 2014 Quidditch World Cup, originally from Pottermore):
Harry Potter Wiki: Troy