The winds of evolution always buffet baseball. Be it integration in the 1940s, franchise relocation in the 1950s, eight expansion teams and the rise of the players' association in the 1960s, Astroturf, free agency and the DH in the 1970s, and steroids, realignment and expanded playoffs in the 1990s, the game constantly is reshaped by its times as surely as a beachhead is by the tides.
Something very different happened to baseball in this last decade. It changed enormously, but almost entirely from within. There was no expansion (expanding only the record streak since the last one to 22 years), no relocation and no major structural change but for the second wild-card added in 2012.