Silver generally goes where probability and historical experience tell him.
Unfortunately for him, numbers and historical experience are only part of the equation. In sports, like in politics and war, human emotion, random chance, and other intangible, un-quantifiable factors occur in reality. However it is impossible to factor them into any algorithm.
Yup. Silver is just an average statistician, with bias thrown in. Looks good when his side wins, looks like an idiot otherwise.