Since the first World Cup penalty shootout ended in victory for West Germany over France in the 1982 semi-finals in Spain, the do-or-die method of deciding drawn matches has created some of the most memorable moments in the tournament's history.
Two finals have been settled by penalties, in 1994 when Brazil beat Italy and in 2006 when Italy defeated France.
"You can read a lot from the body language of the player and where he is thinking of placing it" Kahn said.
"It is a psychological duel between the goalkeeper and the penalty taker. It has a lot to do with eye contact and body language.
"You can irritate him with your body language, you can see whether a player is fearful and you can see from his eyes if he makes a small mistake into which corner that ball will go."
"If you have three seconds to read the body language, its easy, but if you have one tenth of a second to read his body language before you can decide what way to go, then it becomes difficult," he dead-panned straight back.
"You have to do your homework, you know where the player can shoot, what his habit is, if he waits for the goalkeeper or if he chooses the corner.
"But you need to be strong, stay calm, try to keep your homework working, then you have a chance of saving it. You have to make yourself big."
Kahn admitted than when his side Bayern Munich beat Valencia on penalties in the 2001 Champions League final, he didn't remember anything he had researched about his opponents.
"I still remember very clearly, I was working with my coach Sepp Maier to figure out what all the players' tactics were. But I forgot all about it. I went straight into a phase of absolute concentration. I couldn't hear the crowd, the supporters nothing."
