This past week at Nationals Park, Stephen Strasburg signed a seven-year, $175 million contract extension. Max Scherzer fanned a record-tying 20 Tigers in a game. Bryce Harper got ejected, cussed an ump, got suspended, appealed his suspension so he could keep playing, then hit a game-winning home run. By week’s end, after a 5-1 loss to Miami on Sunday, the Nats were in first place in the National League East by one game as they head to New York to play a three-game series with the Mets, starting Tuesday.

Amid all this news and noise, one significant event was partially overlooked. Between games of a day-night doubleheader Saturday, when it would get the least possible attention, the Nats announced they had picked up their two-year option to keep Mike Rizzo as general manager through the 2018 season. The cost to keep Rizzo was $2.5 million a year, the same as his current deal.

It is hard to measure the value of a general manager — and the front office and scouting staff that he hires and runs — with any great exactitude. But it is easy to get a general sense of the size of that contribution. Baseball has flawed but valuable methods to guesstimate a player’s total value: wins above replacement. Look at many players over many years, and the general picture probably will be valid.

[Nationals pick up Mike Rizzo’s two-year option]

In the case of Rizzo and his organization, that picture is stunning. And it is the reason the Nats not only will be competing for an NL East crown this year but probably in 2017 and 2018, too. “Now that [Strasburg] has been extended, it looks like almost this whole team is in place through ’18,” said Jayson Werth, whose deal runs through next season. “I hope I’m still around to see it all.”

Two players, Werth and Ryan Zimmerman, signed deals for $126 million. Scherzer got $210 million as a free agent. Those deals ultimately end at the door of the team owners, the Lerners. But all the rest — 22 out of 25 players on the roster — were scouted, drafted, developed or traded for by Rizzo and his people. Only Oakland, with GM Billy Beane, has a higher proportion of its roster acquired by trade.

Here’s a partial list, just from Sunday’s lineup: Ben Revere was acquired for Drew Storen, who has an 8.25 ERA in Toronto. Catcher Wilson Ramos came in a deal for reliever Matt Capps — a steal. Starter Joe Ross, a rising star at 22, was in a trade, along with top prospect Trea Turner, for Steven Souza Jr., a serviceable outfielder in Tampa Bay. Someday, that may be one of the best deals Rizzo ever makes.

Starting pitchers Gio Gonzalez and Tanner Roark, as well as relievers Jonathan Papelbon, Felipe Rivero and Blake Treinen, plus backup catcher Jose Lobaton came in trade. The best man lost? Maybe Nate Karns.

Since becoming GM in 2009, Rizzo has made trades that have, by my estimate, brought about 25 extra wins to the Nats above what might be expected of an average GM who cancels a good trade with a bad one. Also, since 2007, Rizzo has been the man most responsible for the Nats’ draft record. Since then, they have added about 40 extra wins above the average front office.

[Nationals bobble away chance to win series vs. Marlins]

That’s 65 extra wins. Is it an exact measure? No. Is it shocking? Yes.

For perspective: Harper’s career WAR: 21.7.

Most other teams can only smack their foreheads. Since 2007, the Nats have added 101.8 wins through the draft (using Baseball-Reference.com’s methods). The exceptionally smart Rays have 57.3, the Orioles 59.7 and the Mets 50.9. Then look with a shudder at the Yankees (24.1) and Dodgers (19.7).

Some may say: How smart do you have to be to draft Strasburg or Harper with the No. 1 overall pick? Let’s pretend Strasburg and Harper never existed and the Nats got 0.0 value from their top picks in 2009 and 2010. The Nats’ drafts still would have produced a WAR of 65.3 — better than most teams.

The Nats’ specialty is eyeball scouting. They have consistently found value in low picks that seldom produce major league players. Souza (100th overall pick), Derek Norris (130), Michael A. Taylor (172), Aaron Barrett (266), Tommy Milone (301), Robbie Ray (356), Tyler Moore (481), Steve Lombardozzi (571) and Billy Burns (967) all became major leaguers. Some played for the Nats; some were used in trades. Rizzo, who was picked No. 554 himself, values such supposed bums.

Finally, in addition to trades and drafted players who already have contributed at Nationals Park, Washington has MLB’s fifth-rated farm system (according to Baseball America), led by shortstop Turner, Lucas Giolito (the top minor league pitching prospect in MLB) and blazing Dominican center fielder Victor Robles, still 18, who’s in his third minor league season and destroying every level. He’s hitting .336 at Hagerstown.

The Nats do their own internal evaluations of trades and drafts, using their own proprietary metrics (similar to WAR). They ain’t tellin’ secrets. But they confirm my numbers are close to theirs.

“I’m sure Mike would say that all of this matters if it ends up in a championship. That’s the goal,” Werth said. In fact, Rizzo does say exactly that: A World Series championship is the main idea.

But there are other measures. Since 2011, only one franchise, St. Louis, has more wins than the Nationals. That’s especially remarkable since the Lerners bought a team — the ex-Expos — that had been run into the ground with everything of value sold or traded off.

“This franchise was a cesspool when we started,” said Rizzo, who was the first employee hired by the Lerners. “It was much worse, top to bottom of the organization, than [the expansion] Diamondbacks were when that franchise started.”

In the next 10 days, the Nats and Mets will play six times. The first major chapter in their head-to-head battle for 2016 will go in the books. Those headlines, like bold type for Strasburg and Scherzer, will obscure the expected news that a GM’s contract has been picked up for two more years.

But the work of front offices adds up over the years. If the addition of 65 wins over the past nine years is even remotely close to an accurate evaluation of their value, what is their contribution in dollars to the Nationals? The baseball industry debates whether, over that period, one extra win — if you had to buy it on the open market in free agent dollars — would have been worth $6 million or 7 million or 8 million. That’s the range.

But what a range! That’s hundreds of millions of dollars. Who says that nobody in baseball is a bargain?

For more by Thomas Boswell, visit washpost.com/boswell.