The Washington Nationals gave fans in D.C., Maryland and Virginia the first shot at tickets for home games against the Phillies, including a three-game series starting Friday. The attempt at blocking sales to those outside the region was part of a "Take Back the Park" campaign aimed at traveling Phillies fans, who have overrun Nationals Park. "This is the first time a team has actively marketed a rivalry," said Joris Drayer, a ticket sales expert with Temple's Sport Industry Research Center. "I think it is quite a good approach."