It's undeniable that the rust that accumulates with five days off hurt the Nats in Game 1 of the NLDS against the Giants. If you can win the Wild Card Game, then having played in it is a huge advantage. Both Wild Card teams won Game 1 of the Division Series this year and it was pretty clear that the Nats' and Angels' timing was off offensively. MLB has to reorganize the playoffs.
The Nats' offense succeeds when Denard Span and Anthony Rendon get on base. They were a combined 1-9 in Game 1. The 3-2 loss was frustrating because it seemed so fluky.
Wilson Ramos made a few great blocks of the ball, but the one he missed was huge. Ramos almost never misses a pitch like that. It allowed two runners to move up and a run eventually scored. One of those two runners were on base because Adam LaRoche was uncharacteristically aggressive defensively. He's usually such a cool customer, but he tried to do too much.
Ramos is also great at throwing out potential base stealers. He threw one out in Game 1. But he didn't get Hunter Pence and the Giants scored a run only because Pence stole that base.
It was also frustrating because Steven Strasburg pitched well, but the batted balls kept finding holes. And Ian Desmond struckout with the bases loaded, but the very next batter, Bryce Harper, launched a monster homerun. Unfortunately, Harper's homer took place in the following inning.
The Nats' defense has been the one area that has shown inconsistency. The Nats can be very good defensively, but they have a tendency to implode every now and again. Still, the machinations of the postseason bit them. The long wait and the torturous four hour 9-inning 3-2 game are two things that are very different than the regular season. Laz Diaz's miserably erratic strike zone didn't help either.