Yes, I more-or-less stole the above title from the 2004 Ken Ross book entitled A Mathematician at the Ballpark . Like that book, anyone familiar with middle-school (or junior high school) math, should have no problem with most of what we do here. However, I will try to go into baseball in more detail than the book did.
Paraphrasing slightly, I read somewhere the following facetious remark:
From a survey of 1000 random baseball fans