There are also many widely-held beliefs regarding numbers in sports. Maybe it's the fact that you're trying to accumulate a particular score, but the numbers don't lie for many athletes. In golf, any ball marked with a number higher than four is bad luck, and any odd-numbered club should be used for your first shot of the round. Football players love double numbers on their uniforms, and of course despise the number 13. The most famous number 13 in football history, Dan Marino, may have put up some big numbers in his playing days, but he only cares about the number of Super Bowl rings that he won: zero.
Many superstitions encourage either the continuation of a streak, or breaking the pattern of a slump. You never talk to your pitcher during a no-hitter, just like you never mention the word "shutout" to your goaltender in hockey. These beliefs reinforce the idea that the pitcher and goalie are positions that require a unique level of focus, and you never risk distracting them. Conversely, a team often employs the rally cap when it is behind, because it hopes to turn its fortunes around with the hats.
The notion that a player or team's fortune is somehow tied to arbitrary measures like these seems rather silly, but superstition does have at least a placebo effect on the athletes who believe in them. These routines give a player a sense of confidence in his abilities, assures him that he is in fact prepared for the game, and takes even the biggest game he will ever play in and makes it feel no different than any other time he steps onto the field. And exactly what is wrong with feeling confident, prepared, and calm before an intense competition?
With something as uncertain as the outcome of a game on the line, superstition and ritual give athletes a small measure of control. And if that allows them to perform at their best night after night, let's put on our lucky shorts and hope this streak continues.