google tangotiger and then read his book. baseball prediction has been done to death by the sabermetrics community but this guy is one of the absolute best.
tango is awesome, but saying he is the best is misleading. He is just one point of view, albeit a fairly wise and proven one. There are many other people with other opinions, using other techniques, and they have gotten good results- He is a bit of a curmudgeon when it comes to modern statistical techniques and machine learning.
edit: sorry, misread "one of the" as "the"...