If the most important MLB pre-game tradition is the shouting of "Play ball!" then the most exciting one is the ceremonial first pitch.
Sometimes the honored throwers are former players returning to their old stadiums. Sometimes they're touring celebrities or visiting dignitaries, and sometimes they're Average Joes with friends in high places.
The most memorable first pitches are the bad ones, from Barack Obama's supposedly feminine delivery to Shania Twain's pathetic little roller.
But on some rare occasions, the first pitches are actually pretty good.
Here is my list of the 10 best first pitches in baseball history, ranked on an Olympic scale of 0-10 based on accuracy and velocity, style, and other intangible qualities.