I'm surprised that someone hasn't created a sports-themed collectible card game that uses real players for the roster.

One of the real magic things about Madden as a videogame is that it has the same teams and players you know, with stats intended to reflect their real-world performance. The result is that you can take all of the sports knowledge you already have in your head from being into football and know that knowledge materially makes you better at this videogame.

Seems like you could do the same thing for a collectible card game and make a mint.