The snap could be bad. The hold could be wrong. Or the kicker could worry that the snap could be bad or the hold could be wrong or he might miss the kick, and that worry is the most threatening possibility of all, because a kicker doesn't throw passes, read defenses, look for the hole, go deep, chase the quarterback, or cover receivers. He spends virtually the entire game thinking about or trying not to think about his next kick. He spends it inside his own head.