The coming weekend of May 16-18 presents a new schedule wrinkle for Major League Baseball and it's been branded "Rivalry Weekend."  To be sure, it's a bit of a contrivance, and Rivalry Weekend notably does not include the sport's most time-honored blood feuds like Yankees-Red Sox,

Division rivalries, city rivalries and Interleague rivalries are on tap this weekend for the inaugural Rivalry Weekend presented by Booking.com. Through Sunday, you can watch every game for free on MLB.

However, there’s a different reason for the designated rivalry here, and it only has a little bit to do with geography. Specifically, how MLB’s divisions used to be aligned decades ago. In the 1980s,