Patrick Corbin -- the man who really replaced Bryce Harper -- is pitching for the Nationals in Game 4

WASHINGTON -- One thing you haven't seen walking around Nationals Park before games in the postseason or in the stadium during games: Bryce Harper jerseys. The Washington Nationals organization moved on from Harper pretty much the moment he filed for free agency. The fans have apparently done the same. We all love our baseball history, but romanticizing the past -- even the immediate past -- doesn't help you win games today.

Indeed, Nationals fans are more concerned about re-signing Anthony Rendon than worrying about what Harper is up to these days:

What has helped the Nationals is signing Patrick Corbin this past offseason to a six-year, $140 million contract. Money that could have gone to re-sign Harper instead went to an elite left-handed pitcher who filled a bigger need -- the starting rotation -- and who has provided an invaluable No. 3 starter behind Max Scherzer and Stephen Strasburg.

Now Corbin, who went 14-7 with a 3.25 ERA in the regular season and has both started and relieved throughout the postseason, has a chance Saturday to put the Nationals within one win of their first World Series title and the first championship for a Washington ballclub since the Walter Johnson-led Senators won in 1924. It could be the perfect exclamation point on the season for a pitcher everyone thought at the outset of free agency would end up with the New York Yankees -- after all, the Yankees needed a starter, they have money, and Corbin is from the Syracuse area.

"No regrets," Corbin said before Game 3 about not signing with New York. "I obviously loved every second here. I always tell everybody I feel like I've been here longer, just such a great clubhouse."

The 2018 Nationals were a disappointment, finishing 82-80 after entering the season as heavy favorites to win the National League East. The rotation was a big reason why, dropping from third in the NL in ERA in 2017 to ninth in 2018. Scherzer was excellent, but Strasburg missed some time, Gio Gonzalez struggled and was traded to Milwaukee, and a couple of youngsters weren't ready for prime time. They wanted a third reliable arm.

Corbin gave them that. In essence, his annual average salary of $23.3 million replaced the $25.4 million average Harper will receive from the Philadelphia Phillies over 13 years. The Nationals arguably got the better -- if less famous -- player as well. Corbin, 30, was worth 5.7 WAR in 2019 per Baseball-Reference.com, and Harper was worth 4.2 for the Phillies.

Harper certainly provided a presence in the middle of the lineup. However, he had been unable to replicate his monster 2015 MVP season and hit .249/.393/.496 in 2018. More problematic was that his defensive metrics were a disaster. Juan Soto's precocious emergence meant the Nationals had a big lefty stick to fill the cleanup spot, plus they wanted to find regular playing time for rookie center fielder Victor Robles, one of the top prospects in the game.

"For me, Bryce chose to go elsewhere," manager Dave Martinez said on the off day before Game 3. "But the guys we've had, we knew that we had the right guys to be able to step in and do the job, we really did. I mean, a healthy Adam Eaton, as you all know, you can see what he can do. We have a young center fielder in Victor Robles that's had an opportunity to play every day this year, and has done well. And a 20-year-old that's going to be 21 here in a day or two that's been unbelievable."

Indeed, the Nationals' outfield defense was vastly improved this season. In 2018, they ranked 26th in the majors with minus-29 defensive runs saved. In 2019, they improved to seventh with plus-25. Via the Statcast measure of outs above average, the outfield went from minus-16 (26th in the majors) to plus-27 (first). Much of that was due to Gold Glove finalist Robles, who led all outfielders with 21 outs above average and 24 DRS. Robles was a big improvement in center field and Eaton was an improvement over Harper in right. Like Robles, Soto is also a Gold Glove finalist.

Corbin has started twice this postseason and relieved four times. He pitched a scoreless sixth inning in Game 1, but as the Nationals pulled away in Game 2 he wasn't needed. "This time worked out pretty well for us being able to throw Game 1 and then having three full days off," Corbin said. It's late in a long season, but his most recent start came Oct. 15, in Game 4 of the National League Championship Series, and Corbin says he feels good: "I didn't throw at all. So I was able to do my same routine, everything that I would have done. A little ways from my last start, too."

Corbin gave up two runs in six innings in his division series start against the Dodgers, and struck out 12 in five innings against the Cardinals. He has thrown more innings than he ever has in a season. Washington pitching coach Paul Menhart said this is the moment a starter works for all season, to leave it all out between the lines. "Not that they necessarily save stuff [in the regular season] -- because nobody really does -- but there is an emptying of the tank, with the thought, 'This is what I trained for, this is what I prepared for, I'm letting it go,'" Menhart said.

Corbin isn't a household name like Scherzer and Strasburg, but he ranks seventh in WAR among starting pitchers over the past two seasons. He had his breakout season for the Diamondbacks in 2018, going 11-7 with a 3.15 ERA and 246 strikeouts in 200 innings. His 2.47 fielding independent pitching ranked second in the NL and he finished fifth in the Cy Young voting.

Corbin said a conversation with Diamondbacks pitching coordinator Dan Haren helped transform him from a good starter into a terrific one. "Talking with Dan Haren one day walking in spring training and we just came up with a couple small things that we thought could help get better, and it made sense and ran with that," he said.

No mechanical tweaks. No invention of a new pitch or a new grip. "Being smarter in counts. You just learn every year, being around the game long enough, facing hitters more and more. Throwing a few more breaking balls," Corbin said.

Corbin had been an All-Star in 2013, his first full season in the majors. He missed 2014 because of Tommy John surgery and returned midway through 2015. In 2016-17, he went 19-26 with a 4.53 ERA. Then, suddenly, he became one of the top starters in the game. In April 2018, he went 4-0 with a 2.25 ERA. He was striking out batters at a higher rate than ever before. His slider had gone from great to nearly unhittable at times. In 2016-17, batters hit .184 against it, with a 44.8% strikeout rate. The past two seasons, batters have hit .150 with a 52.6% strikeout rate.

Corbin's slider is unusual in that it's not a power slider as you usually see from a guy with above-average velocity. In some ways, it acts more like a curveball: above-average movement with below-average velocity. Corbin said the key is that it looks like his fastball coming out of his hand.

The biggest change, however -- and this is perhaps what Haren was getting at -- is that Corbin started throwing fewer four-seam fastballs and more two-seamers (and more sliders, particularly compared to 2016). Batters had slugged .523 against his four-seamer in 2016 and .471 in 2017. It made sense to throw it less, to not rely on it so much when behind in the count. To get smarter.

It doesn't hurt being around a rotation that includes Scherzer, Strasburg and wily veteran Anibal Sanchez. Strasburg told me how he likes to watch other starters' bullpen sessions, even if they are different types of pitchers from himself. The other starters will do that as well from time to time.

"Sitting in the dugout, talking to whoever's not in there, I think it's huge," Corbin said. "What they see out there is maybe different from what we see, or vice versa, so it's great to have those guys with their experience."