It's difficult to determine the exact reasons why the 2004-2005 era was a "magical year" for sports games, but several factors may have contributed to this trend:

1. Advances in technology: The 2004-2005 era was a time when game consoles were transitioning from the sixth to the seventh generation, and developers were starting to take advantage of the improved hardware to create more advanced and immersive games.

2. Competition among developers: With the sports gaming market becoming increasingly competitive, developers were working hard to produce high-quality games that would stand out from the crowd and appeal to fans.

3. Fan feedback: With the growth of online communities, game developers were able to receive direct feedback from fans and use it to improve their games.

4. Rising popularity of sports games: Sports games were becoming increasingly popular, and developers were eager to capitalize on this trend by creating games that would appeal to fans of different sports.

Ultimately, the 2004-2005 era was a time when many factors came together to create a perfect storm for the production of some of the best sports games of all time.