There is ego: Superstars (see Italy's Roberto Baggio in the 1994 World Cup final) convert only 60% of their kicks compared with 75% for non-superstars.

WSJ: Euro 2012: An Apologia for the Penalty Kick Shootout

Roberto Baggio took the spot kick and scored the winner.

BBC: 1994: A bridge too far

That left Brazil, led by Romario, carrying the South American challenge, while Italian Roberto Baggio hauled his team through the knockout stages in a trio of match-winning performances against Nigeria, Spain and Bulgaria.

CNN: STORY HIGHLIGHTS