Can someone explain what R^2 is in "lay man"'s terms? I understand it to be that if R^2=1.00 then that means the CAPM model can explain 100% of the real observed data. If R^2 is .99 then 99% of the data fits into the capm model? What about "adjusted" R^2... Or better yet what would be a *GOOD* statistics 101 book that can explain these things like Feynman could in physics or Thompson in calculus....? Most textbooks are reference books and completely worthless/waste of time/ high risk:reward in terms of trying to learn from them in a short period of time. Thanks.