One reason the Nationals have improved by at least 10 games each year from 2010 through this season is that they have solidified positions in their lineup that once were question marks. Rookie Bryce Harper has done his share in the outfield since being called up April 28. (Associated Press)

One reason the Nationals have improved by at least 10 games each year from 2010 through this season is that they have solidified positions in their lineup that once were question marks. Rookie Bryce Harper has done his share in the outfield since being called up April 28. (Associated Press)