The Algerians had a secret weapon. They employed local Zulu magicians or witchdoctors called Sangoma. The sangoma has to satisfy a demand for 'umuthi' (medicine) to prevent misfortune.
In South Africa, all football teams have a sangoma who is taken very seriously and travels with the team to all matches, he asks his ancestors to help them win, when they arrive at the field where they will be playing, he puts a magnet behind the opponent's goalposts to attract the goals and attaches a padlock to theirs to 'lock out' the opponents goals. This is changed around at half time.
The Algerian coach used a Sangoma to facilitate a draw, knowing that he did not need to win now to obtain qualification, as the US, with its more spiritual players (more Americans believe in God than in England, and are thus more superstitious)would be more vulnerable to the local magic.
The Sangoma changed his spirit into that of a magic pigeon, who sat on the goal throughout the game, willing the ball to stay away from the Algerian goal. He didn't even bother changing halfs because he knew his magic was very powerful.
The Sangoma used by Algeria was a descendant of spirit warriors who won the battle of Isandlwana.