4. Wearing thin
Despite dropping Juan Manuel Marquez three times in the first round of their first meeting in 2004, Manny Pacquiao was fought to a draw by the Mexican. After the fight, Pacquiao claimed he could not perform as well as he had wanted because he was wearing the wrong socks. He said the ones he had worn were too thin and gave him blisters during the bout, affecting his movement. While plausible, it seems strange the Filipino icon would have chosen to wear either very cheap or very old socks for such an important fight.