Keeper Jens Lehmann was handed notes before each kick to give him an edge in Germany's shootout win over Argentina.
Lehmann plunges to save another penalty
Lehmann, who saved two penalties, was given a slip of paper before each kick detailing where the kicker was likely to put it.
Coach Oliver Bierhoff said: "He watched videos of all the penalties Argentina have taken in the last two years.
"He then consulted notes with our goalkeeping coach because you don't know who's on the list until the time."
Few noticed the move at Berlin's Olympiastadion, which was mastermined by Germany's Swiss-born chief scout Urs Siegenthaler.
Bierhoff added: "Before our knockout games against Sweden and Argentina we gave Lehmann information on the possible penalty takers.
"We then just told him to save two penalties, in case he forgot."
Germany have never lost a penalty shoot-out in a major competition, though the former West German team did lose to Czechoslovakia in the 1976 European Championship.