With that question centering around the Nationals' top tier pitching options, my esteemed colleague (a suffering Mets fan) posed this: would the Mets be the rare underdog that actually would have a better chance against the Nationals in a 5-game series, as opposed to a one game playoff?
Generally, an underdog wants a shorter time frame to try to pull off the upset - less time equals more randomness, and less of a chance for talent to win out. But the Mets are one of the few teams in baseball that could match the Nationals' pitching staff, with three aces in the top 10 of NL pitcher WAR (plus the NL Rookie of the Year, and still didn't make the playoffs).
So consider an alternative reality in which the Mets make the playoffs, and face the following proposition: they have to face the Nationals in a one game playoff, or a full five game NLDS (in both cases Washington has home field advantage).
Do you want to roll the dice on one game, with your best pitcher (Jacob DeGrom) up against their's (Scherzer)? Or would you rather have your lineup of DeGrom (#1 in NL pitcher WAR), Wheeler (#7), and Syndergaard (#10) go up against Scherzer (#2), Strasburg (#3), and Corbin (#6)?
Over 10,000 simulations, the Nationals win 61.8% of the time in the one game playoff (this also serves as Game 1 of the NLDS). Here are the game-by-game probabilities over a five game series:
It's actually incredibly close - Washington would only have a 0.5% edge (62.3% favorites) in the NLDS scenario compared with the wild card game.
But, as expected, the Mets would still (barely) prefer the randomness inherent in one game over a five game series.