Article snapshot taken from Wikipedia with creative commons attribution-sharealike license.
Give it a read and then ask your questions in the chat.
We can research this topic together.
Each of the continental champions from five federations received an automatic berth. Alongside the seven teams qualifying through the 2004 Men's Field Hockey Olympic Qualification Tournament, twelve teams competed in this tournament.
Although the host nation would have qualified automatically as well, the International Hockey Federation (FIH) and the International Olympic Committee (IOC) refused to give them an automatic berth due to the standard of hockey in Greece. Greece appealed the decision to the Court of Arbitration for Sport (CAS), however it was turned down. Greece's first option to gain a place at the Olympics was by qualifying for the EuroHockey Nations Championship held in 2003. As they did not qualify for this tournament their last option was to beat Canada, the last ranked team of the Olympic Qualification Tournament in a best of three play-off competition. Canada would have kept its place in the Qualifier regardless of whether it won or lost against Greece. There would, however, have been six places at stake at the tournament if Greece had qualified, rather than the seven eventually available. Greece lost the first two matches against Canada, losing their chance to qualify to the Olympics.
Umpires: Raymond O'Connor (IRL) Jonathan Wright (RSA)
Final ranking
As per statistical convention in field hockey, matches decided in regular time are counted as wins and losses, while matches decided by penalty shoot-outs are counted as draws.