When Juan Nieves threw the Brewers franchise’s first no-hitter back on April 15, 1987, scant souvenirs survived.

“We kept his jersey and hat, and I think we had one ball from the game,” said Brewers longtime director of clubhouse operations Tony Migliaccio. “In those days, the guy with the best penmanship on the team would write the date on the ball and put it in a case.”

Contrast that with the night of Sept. 11, 2021. Corbin Burnes and Josh Hader combined on Milwaukee’s first no-hitter in 34 years, and there were enough items professionally authenticated from the evening to fill a small museum.

Baseball fans have been collecting keepsakes for as long as anybody can remember. But only in the 21st century has the sport developed and perfected a system for gathering and verifying game-used objects -- balls, bats, cleats, helmets, hats, bases, lineup cards, stadium dirt and on and on and on -- that prevents fraud, preserves history and, yes, provides revenue.

The 2021 season marks the 20th anniversary of a process that is innate to the modern Major Leaguer but not as commonly known to fans. MLB’s first-of-its-kind authentication program is the most comprehensive collection system of any sports league, documenting hundreds of thousands of pieces of memorabilia every season.

“We’re here to record history,” said Michael Posner, MLB’s director of authentication. “It’s something the league will look back on in 50 years and be able to say, ‘Thank goodness we had a process for recording all of this, because now we know where everything is and there’s no question about it.’”

Questions about supposed souvenirs are how the authentication program came to be.

Back in the late 1990s, a visitor to an official Padres gift shop spotted items purportedly signed by Tony Gwynn that he knew to be fake.

How did he know? Well, that store patron was Gwynn himself.

The San Diego field office of the FBI was alerted to the situation, and Gwynn participated in a probe of forged autographs and fake sports memorabilia that was known as “Operation Bullpen.” The investigation’s first phase, which was completed in April 2000, resulted in the charging of 26 individuals, all of whom were convicted. When the probe expanded outside of southern California for phase two, another 36 individuals were convicted and 13 forgery rings were broken up.

At the time, it was estimated that more than half of all autographed items in the marketplace were phony. (One conspirator had joked with an undercover agent that Mickey Mantle still had one arm out of the grave signing autographs.) Even if an item came with a “certificate of authenticity,” it was not to be trusted, because the certificates were being forged, too.

“As a league,” said Posner, “we became aware of that and decided to do something to protect our players, fans and teams so that they’re not getting ripped off.”

The authentication program began in 2001, with the help of an outside accounting firm, and took a few years of fine-tuning. But by 2006, the program in use today had basically taken shape.

Here’s how it works:

MLB has 220 official authenticators, all of whom are either active or retired law enforcement officers.

“What we’re doing is really evidence collection,” Posner said. “We utilize people who are fully vetted. We know their backgrounds very well.”

Two authenticators are present at every Spring Training and regular season game, with upwards of a dozen on-hand for jewel events like the All-Star Game and World Series. Before the game, they meet to discuss what’s at stake on a given day – a player making his debut, a player chasing a particular milestone or anything else that might make that particular game stand out from the norm. And then, during the game, from their spots next to the dugouts, the authenticators’ job is to document the life and times of every game-used ball – who throws it, who hits it, who fields it.

Once a ball is no longer in play, the authenticator retrieves it (often from the ball boy or girl) and affixes it with a small silver sticker. That sticker is the backbone of the authenticator program. Each one is marked with a tamper-proof hologram and a unique letter code. The code is matched in a database where the authenticator has chronicled the use of the object in question, be it a ball, bat, base, etc.

In recent years, the documentation of the game-used balls has been expanded to include corresponding data from Statcast -- the pitch velocity at which it was thrown and the exit velocity it reached after it was struck.

“The first thing we tell the authenticators is to forget everything they know about watching the baseball game because they’re going to look at the sport a different way,” Posner said. “There’s a history attached to everything. You never know when the next no-hitter or four-homer game will take place. Or just a regular game on a Tuesday night, there’s always something happening. Each ball is connected to unique outcomes and really captures the poetry of baseball and all the things going on during a game.”

For the truly historic moments -- such as Hader getting the last out of the record-breaking ninth no-hitter of the 2021 season or Miguel Cabrera smacking his 500th career home run – the authentication program is vital in ensuring that a chain-of-custody record is kept for the pertinent items involved. The balls used by pitchers against Cabrera when he was sitting on No. 499 were all specially marked with an “M,” a serial number and a unique marking visible only with an ultraviolet light so that they could be verified if/when a lucky fan caught No. 500, and his entire uniform was authenticated after the game.

When the program was in its infancy, authenticators had to literally chase this history. When the Cardinals clinched their 2006 World Series title with a strikeout, catcher Yadi Molina was initially perplexed as Posner approached him on the field.

“What’s up, papi?” Molina asked.

“Last-out ball, we need to authenticate it,” Posner replied.

Now understanding the situation, Molina, in full catcher’s gear, gave Posner the ball and wrapped him in a big bear hug.

The embrace of the program has only grown in the years since. Today’s players now know what to do – and who to look for -- when history happens. Cubs first baseman Anthony Rizzo, for instance, caught the last out of the 2016 World Series -- the North Siders’ first championship in 108 years -- and immediately stashed the ball in his back pocket, awaiting authentication.

“We got to him, and he knew exactly why we were there,” Posner said. “He was smiling and holding up the ball for us. Right after we authenticated it, he was as happy as a 12-year-old kid.”

Of course, the vast majority of objects collected are not of major historical significance. But that doesn’t mean they’re not significant to somebody. Players freshly called up from the Minors always love to get the ball from their first base hit. And fans love to get their hands on game-used items, making them valuable fodder for team shops and charity auctions.

Alas, not every item can be authenticated. Because individualized serial numbers, a la the Cabrera balls, are only used for major historical circumstances, home runs hit into the stands are typically not verifiable, unless the ball never leaves the authenticator’s line of sight. (Although, in a 2020 regular season played entirely without fans in the stands, MLB was able to authenticate nearly every home run ball for the first time.) The authenticators hold themselves to strict standards.

“Some items we get in the clubhouse and have to call ‘team-issued’ or ‘player-collected,’” Posner said. "We are transparent so that if an item does change hands, we’re saying as much as we can say and the person acquiring it can make the same determination.”

In the aftermath of this summer’s MLB at Field of Dreams game, home run balls collected in the corn field were not distinguishable from each other and from batting-practice balls, so they could not be verified.

But Posner’s team did the next best thing: They authenticated the corn stalks themselves.

“I was like, ‘The corn’s the thing,’” Posner said. “It’s a big part of the movie and what we set up. So we found a patch in the outfield, and I pulled about 10 or 12 stalks and we authenticated them [with stickers] on the leaves and had them shipped back to the warehouse. I do those things because I know fans will think it’s cool and get a kick out of it.”

The Field of Dreams Game was an example of the good the program can do in the community. Authenticated items from that game between the White Sox and Yankees were auctioned off, with more than $200,000 raised for MercyOne Dubuque’s Cancer Center.

So whereas the baseball memorabilia world once enriched forgers and thieves, today it can benefit much more worthy causes. And fans have peace of mind that any items obtained with that special sticker are the real deal.

“It’s a way for fans to connect to the game,” Posner said. “There’s a young boy or girl out there who would love to have a baseball their favorite player threw or hit. Now we’re able to offer that.”