The number of games between interleague rivals will be reduced under Major League Baseball's new schedule format for 2013. That means fewer battles between the Yankees and Mets, Cubs and White Sox, and Dodgers and Angels. In most instances the rivalry games will be cut from six to either four or three. The new format was caused by next year's move of the Astros to the American League, creating two 15-team circuits and the need for interleague play throughout the season. "It wasn't fair to have six games against an opponent that other teams in your division didn't," Union head Michael Weiner said. "The Mets, for example, would say `Why do we have to play the Yankees six times every single year when some of our division opponents are playing teams that aren't traditionally as strong? We understand we've got to play the Yankees every year. That's OK. Why should we play six?"