Two teams that have helped themselves in the National League playoff picture with impressive runs of late will take nearly identical records into a three-game showdown beginning Friday afternoon when the Washington Nationals visit the Chicago Cubs. The Nationals (70-57) won for the ninth time in their last 11 games at Pittsburgh on Thursday night, hours after the Cubs (69-58) completed a three-game home sweep of the San Francisco Giants. Left-hander Jon Lester (10-8, 4.23), the Cubs' lone losing pitcher in the earlier series, is slated to pitch the opener for Chicago, which begins the series in first place in the NL Central.