Five minutes on the clock, 50 players to ponder. They either played for Borussia Dortmund, Bayern Munich, both or neither.
Remember to tweet your scores @FourFourTwo, and challenge some friends!
NOW TRY Quiz! Can you name every player to score in a Klopp vs Guardiola game?
Today, Bayern Munich and Borussia Dortmund lock horns once more in the latest instalment of the biggest match in German football.
Over the years, it's been Bayern and BVB vying for the top two positions in the Bundesliga. The Bavarian giants usually come out on top - not least when these two teams met in the 2013 Champions League final at Wembley - though Jurgen Klopp managed to win two titles at Munich's expense during his tenure at the club.
Plenty of players have lined up for both of Deutschland's superpowers too. The most high-profile ones were those poached by Bayern - though there are others on our list too who just happened to play for both.
Can you tell your Bayern from your Borussia, though? Five minutes on the clock - we want you to tell us who played for who.
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