One thing you can say about the National Baseball Hall of Fame in Cooperstown, N.Y.: It knows how to connect the dots when it comes to baseball history.

In the YouTube series called Hall of Fame Connections, produced by MLB Network and made possible by a grant from I LOVE NY/New York State’s Division of Tourism, the Hall of Fame focuses on how the 7 train connects to Walter Johnson.

The series, driven by Camping World, looks at the Hall of Fame’s collection from a new and exciting angle, with each episode telling a different story of how two seemingly unrelated artifacts in the museum’s vast collection connect to each other, crossing through generations of baseball history.

Each two-part episode features both a narrative storytelling element that weaves through the history of some of the museum’s most iconic artifacts, and the Hall of Fame’s curators conversing about those artifacts and stories with MLB Network personality Carlos Peña, a former MLB All-Star, and sports journalist Lindsay Berra, Yogi’s granddaughter.

The series consists of 13 episodes, all available to stream for free through the Hall of Fame’s YouTube channel at youtube.com/baseballhall. New episodes will be released each Wednesday through September and will also be featured across MLB Network’s studio programming.

The fifth episode, titled “From the 7 train to the Big Train,” is available now.

Whenever a great play is made in baseball, the Baseball Hall of Fame makes sure it gets a piece of history. Here is what to expect from the fifth episode.

Meet the Mets (and Mr. Met)

The Mets were born in 1962, and a year later, fans could collect a souvenir vinyl record called “Meet the Mets.” The cover of the single featured an illustration of Mr. Met. A year later, Mr. Met became a larger-than-life Major League mascot who had a baseball head. Mr. Met’s companion, Mrs. Met, was created soon thereafter by owner Joan Payson, who was given the idea by a friend at dinner, according to Berra.

The 7 train

The famous 7 train can take you to Willets Point in Flushing, N.Y. In front of the station is Citi Field, where the Mets play. Before the stadium was built, the Mets played at Shea Stadium from 1964 to 2008. In its first year of existence, history was made on Father’s Day, June 21, 1964. Phillies right-hander Jim Bunning pitched a perfect game against the Mets. Bunning’s Phillies cap from that game is now displayed in Cooperstown.

The wrong side of history

Tracy Stallard was on the wrong end of history twice in his big league career. As a member of the Mets, Stallard was the losing pitcher in the Bunning game. He started the game and pitched 5 2/3 innings, allowing six runs on seven hits in a 6-0 loss to the Phillies. Three years earlier, Stallard was a member of the Red Sox on Oct. 1. On that day, he allowed Roger Maris’ 61st home run, which broke Babe Ruth's single-season home run record. Maris’s bat and the ball that was clobbered by Maris that day are now displayed in the Hall of Fame. The fan who caught the ball in the right-field stands, Sal Durante, received $5,000 for it, which is now worth $45,000, according to the Hall of Fame.

Ruth hits 60 in ‘27

In 1927, Ruth set a Major League record by hitting 60 home runs. Those dingers helped the Yankees win 110 games that year. Twenty-eight of those home runs were hit with one bat, which is now displayed in Cooperstown. Each one of those home runs is represented by a notch Ruth marked on the barrel.

Goodbye to the big train

Ruth hit his record-setting 60th home run against the Washington Senators on Sept. 30, 1927. It was also the last Major League game for pitching legend Walter Johnson, who was affectionately known as the “Big Train.” Johnson was given the nickname by journalist Grantland Rice, who likened Johnson’s fastball to a speeding locomotive. Johnson didn’t pitch in his final game; he entered the game as a pinch-hitter for starter Tom Zachary in the ninth inning, and for good reason. Johnson had a .348 batting average that season. Johnson ended up flying out to Ruth to end the game. Johnson wasn’t known for his offense, but he was one of the best pitchers who ever lived, winning 417 games with a 2.17 ERA and record-setting 110 shutouts. Johnson’s Senators uniform is now displayed in the Baseball Hall of Fame.