The best first year players, by OPS+, post-integration (min 100 games played): 1. Fred Lynn, 1975, 162 2. Albert Pujols, 2001, 157 3. Ryan Braun, 2007, 154 4. Mitchell Page, 1977, 154 5. Alvin Davis, 1984, 147 6. Frank Robinson, 1956, 143 7. Gil McDougald, 1951, 142 8. Dwight Smith, 1989, 141 9. Mike Hargrove, 1941, 140 10. Jeff Bagwell, 1991, 139 Got to figure Trout is going to slide in that list somewhere at this point. Oh, and including pre-WWII, the best first year was 1939 Ted Williams. EDIT: Piazza/McGwire don't make the list because their rookie years weren't technically their first years.