By Nick Selbe The two Fox Sports analysts love to go back and forth with baseball’s biggest rivalry, but A-Rod got the upper hand here. The rivalry between the Yankees and Red Sox runs deep—even among former players. As Fox Sports continues its annual coverage of the MLB playoffs, analysts Alex Rodriguez and David Ortiz often get opportunities to revisit the old days of competing on the field. With Ortiz’s Red Sox not in the postseason this year, that leaves Rodriguez with plenty of room to bask in victory, and he took an opportunity to pull a fast one on an unsuspecting Ortiz following New Yo…