I often peruse Baseball Reference. Generally speaking, it contains all the information I could ask for – at least from a historical perspective. If you’ve ever read my writing, you may have picked up on which stat I – rightly or wrongly – value above all else: WAR.
Wins Above Replacement is intended to be the most comprehensive way to assess player value, compare between eras, and compare entirely different positions, like shortstops and pitchers. The way WAR is calculated varies at each site where it’s calculated, like at Baseball Reference or at FanGraphs. Here is the BBRef calculation of WAR, and here is the FanGraphs version, if you’re interested.