Major League Baseball wants to make Rivalry Weekend something that has organic juice and the results to this point suggest that they need to squeeze a bit harder. The latest edition hits over the weekend as a full slate of interleague action highlights many battles for regional supremacy. Due to the entirely inequitable state of play to this point, the Guardians-Reds matchup and the Cubs-White Sox crosstown engagement are the only two where both teams enter with winning records. The Subway Series is back in effect with the Mets currently riding high after walloping the lowly Tigers in a three-game sweep and the Yankees looking to keep pace with the Rays in the AL East. Elsewhere, the Red Sox and Braves square off as one team looks to remain red-hot and the other seeks a spark while the Giants battle the Athletics with the ghosts of Bay Area past looking on.…