The Washington Nationals will have 25 players on their World Series roster, but if all goes according to plan, Manager Dave Martinez won’t use all of them. The postseason heightens the importance of each out, of each pitch, and the depth that helped the Nationals get by in the regular season is mostly moot. For the Nationals, a team that hardly ever matches up, the postseason is about the best players because they’re the ones on the field for those critical moments.

During the first three postseason rounds, Martinez shrank the roster. He relied on 17 players, and his managing underscored the reality of his team. It is top-heavy, so he limited the exposure of his weakest link — the front end of the bullpen — by experimenting with extremes to give his best pitchers the most innings. He stitched together outs with the two relievers he trusted, Sean Doolittle and Daniel Hudson, as well as one of the other starters from his high-paid, high-performing rotation.

The starters are this roster’s backbone, and now they’re a key to why the Nationals once-historically bad bullpen has transformed into a strength this postseason (22⅓ innings, 0.81 ERA, excluding Games 1 and 3 of the National League Division Series).

This drastic tactic is reminiscent of the 2018 Boston Red Sox, and Martinez signaled he would deploy it in the NL wild-card game. He used his two best pitchers, Max Scherzer and Stephen Strasburg (in his first career relief appearance), to plow through 24 outs. The strategy only seemed viable in a one-game playoff — starters need rest, right? — until Martinez doubled-down in Game 2 of the NLDS. He surprised the Los Angeles Dodgers by tapping Scherzer to hold a two-run lead in the eighth. His perfect inning helped send the series back to Washington tied at 1 and set the team’s template for the rest of the playoffs.

The thought process behind starters-as-relievers was simple: The best pitcher available in the moment should take the mound and give the team the best chance to win. The strategy might have strained those arms if they had been asked to cover too many innings. But they never were, because the starters stayed dominant at their day jobs.

From Game 4 of the NLDS to Game 3 of the NL Championship Series — the Nationals’ most critical stretch of the season as they staved off elimination in one series and built an insurmountable lead in another — the rotation dominated. Those outings: seven innings, one run; six innings, three runs; 7⅔ innings, no runs; seven innings, no runs; seven innings, no runs.

Those showings bridged the dangerous middle innings and handed the relievers a small lead to protect with a reasonable number of outs left. The one night the Nationals didn’t have both trusted relievers — Hudson missed Game 1 of the NLCS to be with his wife for the birth of their third child — fourth starter Aníbal Sánchez carried a no-hitter for 23 outs before Doolittle secured the final four.

Even when the strategy failed — starter Patrick Corbin allowed six runs in two-thirds of an inning in relief during Game 3 of the NLDS — Martinez stuck with it. He went back to Corbin in Game 5, and the left-hander rewarded him with 1⅓ scoreless innings.

The Nationals have recorded 219 outs in their eight wins, and 208 have come from the team’s top six pitchers (four starters, two relievers). The other 11 came from two relievers: Tanner Rainey (eight), a hard-throwing right-hander Martinez is gaining trust in, and veteran Fernando Rodney (three) at the end of a blowout win.

The Nationals maintain this strategy in the lineup. Their bench isn’t a weakness, but they don’t pinch-hit often (outside the pitcher’s spot twice in 10 games). The starters’ dominant outings have prioritized keeping them in the game, and the team wants its best hitters taking the most at-bats. The Nationals only really have two situational, late-game moves: Brian Dozier replacing Howie Kendrick at second base for defense and, now that center fielder Victor Robles has returned from his right hamstring strain, Michael A. Taylor entering the game as a pinch runner and defensive replacement. The other three reserves — outfielder Gerardo Parra, first baseman Matt Adams and infielder Asdrúbal Cabrera — are mainly pinch hitters who have each pinch-hit three times this postseason.

If situations get out of hand, as they did in Games 1 and 3 of the NLDS, the Nationals’ approach shifts. The deficits grew too sizable to stopgap with elite arms, so the Nationals used the front end of the bullpen, the relievers Martinez otherwise shies away from. In the World Series, this probably means Austin Voth, Javy Guerra and Roenis Elías (none of whom appeared in the NLCS), plus Rodney. Martinez used Cabrera at second to finish that Game 3, too, to keep the former starting second baseman in rhythm.

But this situational tinkering only underlines the truth of October. Postseason play prioritizes the top of the roster. This favors one like that of the Nationals, and Martinez won’t forget that. Perhaps the most telling example came in Game 2 of the NLCS.

The Nationals held a 3-1 lead headed into the ninth inning, with the game going exactly according to plan. Scherzer dealt for seven innings, and Doolittle navigated around a one-run double in the eighth. Martinez didn’t want to send Doolittle back out because he had thrown 21 pitches, but he wanted a left-hander to face the Cardinals’ Kolten Wong, a left-hander who is effective against right-handers. Wong was dangerous if he reached base, as evidenced by his walk and steal of second base earlier in the game.

Martinez called in his only other viable southpaw, Corbin. The move might have seemed over-aggressive — Corbin was due to start Game 4 — but it worked. Wong bounced out to second. Hudson entered and retired the next two batters, and the same strategy they had used to avoid a 2-0 deficit in the NLDS now gave them a 2-0 lead in the NLCS. It’s an approach they wouldn’t mind repeating.

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