Still other shelves are packed with collections of bloopers, weird weather events and interviews with big names whose lives have intersected with baseball, including politicians like George W. Bush and Barack Obama, filmmakers like Ken Burns (who’s been using the library to research his upcoming documentary, The Tenth Inning), and entertainers like Billy Crystal and Garth Brooks.

Earlier, a MLB public relations guy invited me to submit a list of great moments I’d like to watch, which I happily compiled. He also suggested I try to “stump the guys” with a few really tough ones. Based on the expertise I’ve already seen, my hidden stump list seems about as intimidating as my fastball, but I’m game.

First, Porciello and stock-footage editor Mike LaManna cue up the films I’ve requested. The first is The Catch by Willie Mays in the 1954 World Series — the back-to-the-plate, over-the-head Polo Grounds stunner that’s on every list of baseball’s greatest plays.

I could stand there for an hour and just watch the play again and again as the flabbergasted announcer shrieks, “There’s a long drive waaaaaay back in center field … waaaaay baaaaack, baaaaack … it is CAUGHT by Willie Mays! ” But, at the risk of sacrilege, I wanted to compare Mays’ miracle to another catch I’d read about but had never seen, this one by Jim Edmunds in 1997. In a moment, Porciello has the sequence up on his monitor, and there’s Edmunds, playing a shallow center field when the batter crushes one. Edmunds turns his back and flees toward the wall. Then he dives, his body fully extended, horizontal to the ground, and takes the ball over his shoulder.

“Might be better than Willie,” Porciello says. “Yeah, but Mays had to get up and throw,” LaManna notes. We watch both plays a few more times, but in the end, I call a draw. It’s like comparing a great Vermeer to a great Monet — impossible.

Porciello shows me a few more gems, and then it’s time for me to “stump the guys.” Yeah, right. The smackdown goes like this:

Me: OK, there’s been only one grand slam in an All-Star game …

Porciello: Yeah, Fred Lynn, ’83. We got it.

Me: Uh, in 1980, a player stole second, third and home …

Porciello: Pete Rose. He was with the Phillies then.

Me (sinking): Uh, there was a famous incident involving the American flag. Who …

Porciello: Yeah, Rick Monday with the Dodgers.

In a flash he’s got the game (April 25, 1976) on the monitor, and there’s Monday dashing in to keep some protestors from burning a flag in the outfield.

I’m out of bullets. Luckily, at that moment, Harold Reynolds, a former major-league star and now an MLB Network analyst, bounces into the room carrying a boxed 16mm film that he’s just acquired but that was shown to him years ago by one of his first coaches. He says it contains footage of Ted Williams hitting in Fenway Park, and he thinks it could be a find for the library. Porciello, though, looks dubious.

“Is it batting practice?” he asks Reynolds. “Is he hitting off a tee? It may be what we already have from the Hall of Fame.”

Porciello doesn’t have the right machine for viewing the film, so he promises to report back in a few days with his analysis. But, as the unofficial memory bank of Major League Baseball, he’s seen it all. And he’s skeptical.

“I kinda think we have it,” he says after Reynolds leaves. “It’s probably something done by MLB years ago.” (A few days later, Porciello’s judgment is confirmed.)

Then it’s time to view one more blast from the past: Carlton Fisk’s homer in game six of the 1975 World Series, the one where Fisk dances down the Fenway Park first-base line, frantically waving his arms as if to keep the ball from going foul. It’s a beautiful moment, but Porciello says there’s more to the story.

“They had two cameras at that game,” he says. “At that time, the cameras were supposed to follow the ball, not the hitter. But the guy shooting from the top of the Green Monster got distracted because a rat ran by his foot, so the camera stayed on Fisk. That’s how they got that shot.”

And now, in this remarkable storehouse of the past, this is how great moments in baseball get preserved, rats and all. Somewhere, the ghost of Babe Ruth is smiling.

World Series Bonanza

What’s the next best thing to touring Major League Baseball’s video library (which, alas, is not open to the general public)? The official Major League Baseball World Series Film Collection.

The Special Edition gift set features 20 DVDs containing 65 World Series films. All the great moments are here: Jackie Robinson’s first World Series (1947), Willie Mays’ amazing catch (1954), Carlton Fisk’s 12th-inning blast (1975), Bill Buckner’s tragic miscue (1986) and the Red Sox win that broke “the Curse of the Bambino” (2004). The set also includes a 58-page World Series pictorial retrospective with an introduction by Bob Costas. $179 to $229,