Several of baseball's longtime rivalries remain as intense as ever, even as new ones have begun to emerge. Red Sox-Yankees: It's cooled but both teams are on the upswing and loaded with young stars, so it should reignite. Blue Jays-Rangers: If only they played more than 7 times each regular season, but they'll make 'em count. Mets-Nationals: Thor has used some colorful language on social media about Bryce Harper and they'll jockey for first in the NL East, as Daniel Murphy looks to haunt his former team. Cubs-Cardinals: Recent player movement between the teams plus barbs traded by the managers adds to the intensity. Dodgers-Giants: This rivalry is so historic that it dates back to both franchises being to the other coast.