WASHINGTON -- In a sense, we've circled back to where we were when the series began just five days ago. The World Series is starting fresh, but the margin of error for both the Houston Astros and the Washington Nationals has shrunk considerably.

With Houston's 8-1 drubbing of Washington in Game 4 on Saturday, the Series is knotted at two wins apiece. The pall that had settled over the Astros when they dropped the first two games at home with their co-aces on the mound has lifted. They have regained the home-field edge, and if Gerrit Cole and Justin Verlander do what they've done all season long, they will be dancing on the field deep in the heart of Texas come Tuesday.

"Now we got our two horses going," Astros outfielder Josh Reddick said. "So it really seems like it's switching into our favor."

"Seems" is perhaps an apt qualifier, because we remain a long way between here and there -- about 1,200 miles and one gigantic game on Sunday night, one pitting two of the best pitchers of the decade in a Game 1 rematch. It's kind of like Leonard-Duran II, but only if the first bout had been halted in the middle rounds and called a draw. On Sunday night, it'll be Houston's Cole, the best pitcher in the majors this season, locking horns with Washington's Max Scherzer, arguably baseball's best hurler over the past few years.

There are others in the running for both labels, most notably Verlander. But you get the idea. For the second time in the World Series, in Game 5 we get a pitching matchup that is about as good as it gets in the big leagues right now. And the stakes could not be higher.

"There was a lot of noise around losing the first two games, and rightfully so, because the Nats had outplayed us," Astros manager AJ Hinch said. "I think we turned it around, and now we've outplayed them for a couple of games. Now we have a three-game series. The winner of two of three wins the World Series."

The first Cole-Scherzer bout came in the series opener, a 5-4 Nationals win. Scherzer collected the 'W' in his ledger; Cole the 'L' -- his first since May 22. Scherzer went only five innings, thanks to a collectively disciplined Houston approach that sent his pitch count soaring in the early innings. Cole went seven but gave up five runs. Washington won, so you give the nod to Scherzer, but it wasn't exactly what we had in mind when the pitching probables were announced.

Now we get a shot at the matchup again, conjuring memories of other great pairings we've seen more than once in a World Series:

World Series with multiple head-to-head ace matchups
1973: Tom Seaver, Mets, vs. Catfish Hunter, Athletics (Games 3 and 6)
1995: Greg Maddux, Braves, vs. Orel Hershiser, Indians (Games 1 and 5)
1996: John Smoltz, Braves, vs. Andy Pettitte, Yankees (Games 1 and 5)
2001: Randy Johnson, Diamondbacks, vs. Andy Pettitte, Yankees (Games 2 and 6)
2010: Cliff Lee, Rangers, vs. Tim Lincecum, Giants (Games 1 and 5)

"I think it's been tremendous," Cole said about the pitching matchups in the series after four games. "I've had a fun time watching the series unfold so far. It's never fun when you're on the losing side of it. The tenacity shown in the first game is something to be admired for sure."

The default assumption, which of course has statistical underpinnings, is that when pitchers and hitters meet more than once during a short time frame, the heightened familiarity benefits the batsmen more than the moundsmen. In this case, it wouldn't necessarily favor one pitcher or the other, but it would work against the hopes of those who want to see an epic pitching duel.

"No matter what, it's always going to be a battle," Scherzer said.

To assume the general truth about hitter-pitcher familiarity applies to everyone isn't that useful in this case. Still, Cole and Scherzer have built enough of a postseason record that we can at least look at how they've fared when making multiple outings against the same team in the same series. The samples are far too small to be definitive, but perhaps we can pick up on some stylistic tendencies.

For Cole, this will be the third time he's faced a team twice in the same postseason series. There has been a major drop in the back half of those repeat outings. To describe it with words: He has slipped from other-worldly to merely awesome.

The two series in question are the 2013 National League Division Series, when Cole, then with Pittsburgh, faced the Cardinals twice, and this year's American League Division Series, when he got two shots at Tampa Bay. In the first outings, he posted a 0.66 ERA with 20 strikeouts and two walks over 13⅔ innings. Other. Worldly. Then in the repeat engagements, he "tumbled" to a 2.08 ERA over 13 innings, with 15 strikeouts and three walks.

"There are always challenges that are involved in [facing an opponent twice]," Cole said. "This being the largest stage that we can get on, certainly with the opponent being so well prepared, [we] anticipate having to respond to some things tomorrow. Hopefully we respond well."

Scherzer has been around longer and logged more postseason innings in general, so he's had seven of these return engagements, including relief appearances. The results the second time around have not been good. Scherzer has a 2.52 ERA with 11.4 strikeouts per nine innings in the first outings; he's at 5.19 with 9.7 K/9 when running it back. In starts only, his ERA jumps from 3.79 the first time to 6.14 the second.

What has he learned?

"It's just going to be a challenge," Scherzer said. "I think the only advantage of this is that I don't face the Houston Astros that much. In the National League, [hitters gaining an advantage] kind of happens a little bit more once you start getting 10 at-bats. Then I think that kind of equals out and maybe a hitter gets a little bit more advanced, because they understand what you're going to do to them."

Scherzer's point might be a cogent one: None of these other multiple outings occurred in the World Series, so they came against opponents who had more a regular-season frame of reference against him. And let's face it -- Scherzer hasn't built a Hall of Fame résumé by exploiting only those who haven't faced him very often. His toolbox is well stocked.

In this case, after laboring through 112 pitches and 23 batters during his five Game 1 frames, Scherzer has to decide whether sticking with his make 'em chase approach needs to be modified.

"The game will dictate that," Scherzer said. "The scoreboard will dictate that. You've got to just get into the flow of the game, and understand where everything's at, where you're at in the lineup, who's up, score of the game, inning, pitch count -- you name it."

Given that we've got only two Cole repeat starts with which to work, we can't read that much into his pitch selection from one outing to the next. The scouting reports against individual lineups and the hitter-by-hitter adjustments are so complex that they overwhelm any trend you might think you see in second starts.

However, with that caveat noted, we can say that in both instances, Cole ramped up his fastball usage the second time around. In that 2013 series against the Cardinals, his four-seam usage jumped from 34% to 49; against the Rays in the ALDS, it went from 53 to 63. His four-seam usage in Game 1 against Washington was 54%.

If he follows the same pattern, the Nats' hitters would see a lot of heat in Game 5. And if you haven't been paying attention, you should probably know that Cole's heat is pretty good. Among pitchers who threw at least 1,000 four-seamers this season, Cole's .597 OPS allowed led the majors. On four-seamers in the upper third of the zone -- high heat, in other words -- that number was .420.

As an offense, Washington ranked 17th in the majors with a .817 OPS against four-seamers. Against high heat, however, it finished fifth at .763. Success against high heat, by the way, is a leading indicator: The top seven teams hitting against that pitch in that area made the postseason this year, and eight of the top nine. The lowest any of the 10 playoff teams ranked in hitting against high four-seamers was Milwaukee at No. 13.

How will Cole adapt?

"They won some two-strike counts," Cole said of the first outing. "They battled. I feel like I've said this a few times since we've been to the postseason -- our opponents have not taken a pitch off. But I feel like the intensity grows as we get deeper into October, just the intent and the certainty on the approaches. And on the focus on the pitches, it just continues to just raise across the board. So you have to deal with that. You have to respond to that."

When you look at the sore spots from Cole's Game 1 performance, the fact that he allowed five runs wasn't so much pitch selection or lack of stuff, but an uncustomary lack of command. By his own account, along with that of his catcher, Martin Maldonado, Cole's fastball was leaking toward the middle of the plate at times, and Washington's hitters took advantage, such as high-ball hitter Juan Soto.

Over the past couple of games, Houston has worked Soto with more breaking balls, and it will be interesting if Cole follows suit. But, again, this is all under the "things to watch for" umbrella, because Cole might look at the Nats' lineup and decide to ramp up his slider usage instead of leaning more on his fastball. This is why we tune in.

"I'm not overly concerned about what they're doing to [Soto]," Nationals manager Dave Martinez said. "I just want him to understand that he's really good when he stays in the middle of the field. He needs to stay in the middle of the field and take his walks."

For Scherzer, the tendency pattern in these repeat matchups is less clear, despite the larger sample. He has gone to his four-seamer about 5% more often in return outings, mostly at the expense of fewer changeups. The fastball usage has moved from 54 to 59%.

In Game 1, he threw fastballs on just 47% of his offerings and instead went heavy with curveballs and sliders. There were eight plate appearances in which Scherzer went with a breaking pitch on the decisive offering, resulting in a single and two walks.

Houston's hitters present a particular challenge. The Astros' OPS ranked second in the majors against hard stuff, first against soft stuff and first against breaking stuff. So for Scherzer -- and all Houston opponents -- it's really a pick-your-poison proposition.

"I still feel that I could execute better," Scherzer said. "And give their hitters just a little bit different look, even though they did get to see me pitch against them and what it looks like."

For Cole and Scherzer, it's banal terms like command and execution that will dictate what kind of Game 5 we get. But as so often is the case when you are dealing with talented professionals, it's the attention to the banal that leads us to the spectacular. That doesn't mean Cole won't vary his repertoire -- he probably will, as will Scherzer. But for two pitchers at the head of their profession, if familiarity plays a role, it might work for them in the form of a creeping sense of dread for the hitters.

That's when a pitching duel becomes special. Two durable, hard-throwing, precision artists with nasty breaking pitches and bulldog demeanors, going toe to toe, with the winner putting his team one win away from a championship. That kind of game is what we thought we might see more than once in this World Series matchup. And it's not too late to get at least one.

The entire season will teeter one way or the another Sunday night, before everyone heads back to Houston.

"I hope I go home with nothing left in the tank," Cole said. "Whether it's tomorrow that is the last time I pitch, or I get the opportunity to pitch another time after that, I just hope I'm just absolutely dog tired by the time I get home."