FP said last night the largest lead the Nats had in '12 was 8.5 games in early September.
That was because the Braves were legitimately good that year. Heyward and Bourn had career years. Chipper Jones was still hitting well. Freeman came on strong towards the end of the season. Simmons had the only good year with the bat (well, 50 games). Their pitching was quite good as well, due to career years from Medlen and Hanson, and a bullpen that was deep as freak. Kimbrel, Venters, and O'Flaherty made for some quick games.
Ironically, I wanted the Barves to beat the Crads in the WC game, simply because we matched up so well against them. That was Gio's dominant year and Detwiler pitched them tough as well. With Sean Burnett, John Lannan, and Tom Gorzalanny available, the Braves would have faced a steady diet of lefty pitching, which they struggled with.
Given how well the Nats were playing going in to the playoffs, if that ball had not been called an Infield Fly, the Nationals would have easily made it to the NLCS, and probably to the WS.
