I always think that learning probability can not only help you to gain more intuition when dealing with scientific relative subjects but also empower you to think the daily life things in a different way. I recommend Introduction of probability [1] since it's easy to study and provides great free video lectures [2].
I have a very rough idea about it and i wanted to learn more. Is this book based out on Baseball statistics any good when i don't know anything about baseball?
it's just the fact that one simple formula drives everything and there is the infinite number of applications - from A/B testing to deriving poker play strategies against opponents based on the small number of observations.
I don't think that lack of knowledge about baseball can prevent anyone from reading this book. The author explains everything by using very simple terms. But you need to have some knowledge of R programming language to run the code samples.