As I talked about last year in talking about seasons before that, seasons are usually made or broken by things you didn't plan for. Injuries of course, but also performances that skew a large distance from expectations. It works in both directions, both surprisingly good performances and sudden collapses. If your team manages to get more of the former than the latter you should have a better than expected year, and vice versa.
EXPECTED / FORSEEABLE
ZNN and Zimmerman pretty much played to expectations after starting fast and slow respectively. Also pretty much doing as he does after a slow start was Espinosa. Lombardozzi gave you the empty average you would have projected. Bryce gave you the everything, but just not quite at star level yet, you would have projected.
The bullpen, which began filling up with good arms in 2010, put together another very good year as a whole with some surprises (Stammen, Garcia) matched with some failures (Lidge, H-Rod). Lannan was Lannan when given the chance. Strasburg was STRASBURG when, you know, still in the rotation. Injury hampered Wang was terrible.
All those offensive injuries - Nicks and bumps happen so even something like Desmond's 30 missed games you can write off as kind of typical. But Morse missed 60 games, Werth half the season, Ramos pretty much the whole thing. That's a lot for an offense to overcome.
Morse's injury saps his power a bit - Mike is supposed to be an imposing presense in the middle of the lineup. He still had a good year but post-injury he didn't quite have the pop fans were hoping for.
Storen's injury - One single notable bullpen injury isn't a big deal*, even if it's the closer, but it's kind of unlucky it happened anyway.
*well it shouldn't be a big deal because you should just plug in your 8th inning guy, who's likely your 1st, 2nd, or 3rd best reliever. The Nats didn't do that at first, instead putting in the unreliable because of age Brad Lidge and unreliable because of talent H-Rod. That worked as well as you might expect. But that's not bad luck, that's bad roster management.
Ummmm... Xavier Nady should have really been not so terrible for the Nats. I guess you didn't expect Flores to be that bad.
Desmond broke out - Ian Desmond went from a liability at the plate to a huge plus in a single year.
A lot of bit players overperformed - Bernadina had the best year of his career. Tyler Moore hit for a higher average than anyone could have hoped. Suzuki and Tracy both performed better than they had in years. While the injuries hurt, these performances helped to ease that pain a good deal.
Gio, Detwiler and Jackson all pitched really well - You probably would have expected Gio to do better in the NL then the AL but almost no one predicted him to be Cy Young worthy (almost noone). You probably would have expected Detwiler to hold his own but he pitched like a #3 or better. You possibly would have expected that Jackson would be a nice pickup but he put together arguably the 2nd best season of his career. Any one of these things would have been nice to have.
Complete injury bounce backs from LaRoche and Werth - We were pretty sure neither could hit as badly as they did the year before but given injury returns are never sure things, were hoping for a nice medium between the terrible and what we had expected going into 2011. Instead they got all the way back
The starter health - The Nats basically had 5 good and healthy starters all year long. Only two other teams managed that, the Reds and the Giants. Sound familiar? What about teams with 4 healthy guys you want to throw out there? Angels, Tigers, Cardinals, Yankees, Rays. See the pattern? This is HUGE.
What's the final verdict? Well it's hard to say the Nats weren't lucky this year. They had a big negative with all those injuries but that was the only big negative. On the positive side the Werth/LaRoche bounceback and the bench player's performances really helped directly overcome that big negative and they also had big positives including a break-out season, nearly complete pitching health, and having no starter underperform.
Does this mean that the Nats are doomed to fall back next year? Not at all, mainly because the Nats are a young team. Overperformance by older players is generally a fluke, just a guy having a year where everything seems to go right. The next year though, you expect a return to normal production. For example Chad Tracy isn't going to hit that well again next year. For young players, though it shifts expectations. Maybe they are this good. You don't necessarily go and predict something as good, but you believe a bit more in what you saw recently than what you had previously expected. Ian may not be able to carry an offense again, but he should be in the All-Star discussion. Gio might not be a Cy Young candidate in 2013, but he's probably still a top 15 type pitcher. The Nats weren't an old team catching lightning in a bottle. They were a young team that combined took a big step foward last year. Maybe that means a settling of feet a game or two back, but a full return is not in the cards.
No, the only thing derailing the Nats next season would be injury or an awful case of bad luck.