"Being a CPA and seeing big spreadsheets and making sure the debits and credits are all equal and everything -- well, listen, isn't baseball all about accountability?" said Hellerstein, who started collecting in second grade. "You look at the scorebook and everything is accounted for: the balls, the strikes, the goods, the bads, and I see an incredible amount of similarity. I just look at a boxscore as being a glorified accountant's worksheet."
The brick building, called "B's Ballpark Museum," is not named for only its proximity to the home of the Rockies. All teams are represented in Hellerstein's collection, and while local history of baseball in Denver is highlighted, it's the classic ballparks -- the ones they try to replicate the intimacy and elegance of today -- that might tug at Hellerstein the most.
A light fixture from the entrance of Ebbets Field is on display, along with the drainage cover that Mickey Mantle tripped over in the 1951 World Series. An old Yankee Stadium turnstile is there too, with seats from the Polo Grounds, Tiger Stadium and Crosley Field, among others.
John Thorn, the official historian of Major League Baseball, visited B's Museum as part of a book tour. He can point out a few who have walked in similar shoes as Hellerstein: Seymour Church, who at the turn of the 20th century ran a baseball gallery in San Francisco that was destroyed by fire, might have been the progenitor. In Florida, Joel Platt has a collection called "Sports Immortals."
There are some individuals who prefer to keep similar collections to Hellerstein's in their homes and out of public sight. Some businesses, too, carry the ambiance that B's Museum has, such as Foley's Pub in New York. About 130 years ago, another New York pub called Nick Engel's Home Plate was the first sports bar, and of course, that meant it was a baseball bar.
"It's a granny's attic kind of museum and endearing for that -- I do not mean to disrespect it," Thorn said of Hellerstein's museum. "The Smithsonian collection is our national attic where there are things of extraordinary value and clear national interest, and then there are oddball things and you wonder, 'Whose idea was it to save this?'
"The idea that Bruce is following, he's following in the footsteps of great collectors and great fans. It's an honorable thing and an admirable thing to collect stuff that reflects his passion for the game and because he's generous and open-hearted, he wants to share it with others. It's all terrific."
Hellerstein gives personal tours of the museum, as does Raelee Frazier, a sculptor "from Dorothy's country" in Kansas who's lived in Denver for 40 years. She calls her work, which has included the molding of 27 ballplayers' hands but has not been limited to baseball, "biography in bronze." She sculpted Roy Halladay's hands in 2011.
A few of her life-size projects are on display in the museum, including Greg Maddux's hands, and they all tell a story.
"He was very tentative when he first saw the wax because it's a warm wax," Frazier said of Maddux. "And they wonder, 'Gee, isn't that going to burn?' And he was still pitching at that time so I think he was still a little concerned. ... You can almost fingerprint a lot of the players that I've molded their hands."
B's Ballpark Museum is a not-for-profit, and admission is $5 for adults.