Five minutes on the clock, 50 players to ponder. They either played for Atletico Madrid, Real Madrid, both or neither.
Remember to tweet your scores @FourFourTwo, and challenge some friends!
Atletico Madrid are sometimes forgotten in the conversation of Spanish footballing rivalries - principally because their city rivals have bigger beef with Barcelona.
It's a funny twist of fate, considering how ready Diego Simeone's side look to start a war with anyone who looks at them the wrong way. Make no mistake, though - Real and Atletico aren't exactly friends.
There's been plenty of history between the two: two Champions League finals, countless battles on the pitch and even smaller subplots. Raul, for example, was a boy from Atletico Madrid's academy, let go at a young age who became the King of the Bernabeu.
And on that theme, we're going to press you today on more players who played for Madrid sides. The question is, which one? We've got 50 players who are going to flash up: just tell us who they played for.
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