NEW YORK -- Commissioner Rob Manfred presided over an Opening Day scene on Monday that caused something of a sensation in New York and beyond.
#CapsOn dominated Trending Topics on Twitter and figures to become an annual tradition. Manfred led a contingent of Major League Baseball and New Era personnel that handed out hats, including 500 to traders on the floor of the New York Stock Exchange. The Commissioner, wearing a special Opening Day cap, pounded the closing bell gavel twice with full force, as sort of an exclamation mark on his afternoon.
• Fans, celebrities, world leaders celebrate #CapsOn
"It's a really exciting day. I think we've distributed 27,000 caps here in New York," Manfred said. "It's a great day to work with our partners at New Era and I think a great way to capture the excitement and tradition of Opening Day.
"When we distributed caps here on the floor, it was darn near a riot -- everybody anxious to get their cap. I think it's a sign of just how many people love baseball."
• MLB's #CapsOn program 
Another notable addition to the Opening Day agenda in 2016 was the staging of three consecutive Sunday openers for the first time: Pittsburgh winning at home against St. Louis, followed by Toronto's victory at Tampa Bay, and then, in Kansas City, the first World Series rematch in a season opener between the reigning World Series champs and Mets on ESPN Sunday Night Baseball.
Manfred had planned to be at the Yankees' postponed opener Monday against Houston; he now heads to Kansas City to watch the Mets and Royals at 4:15 p.m. ET on Tuesday.
"I was in Tampa yesterday for the opener -- I wanted to make sure I was at one of the three games," Manfred said. "I think the tripleheader on Sunday is a real improvement for baseball. It gives us an opportunity to own that first day of the season, on a weekend, when people are available to watch lots of baseball.
"Opening Day has always been a symbol for me of starting over again. I couldn't wait for this Opening Day. I'm really excited about the 2016 season and can't wait to get going."
Right after the opening bell at the NYSE, former New York pitchers Jeff Nelson from the Yankees and Bob Ojeda from the Mets walked through the floor handing out caps representing their former teams. By the time the Commissioner arrived at 3:30 p.m. ET, along with an entourage that included former players Willie Randolph, John Franco and Ojeda, the caps were en vogue.

"It's great, everyone representing their team, their enthusiasm, you can feel it here," Randolph said. "It's a fashion statement nowadays. Everyone wears hats. New Era and Major League Baseball do a great job of promoting it. I love hats, I collect hats, I have thousands of them. So I feel very comfortable with it on. It's just nice to see everyone representing their team and having fun with it."

For Randolph, Opening Day always creates a unique stir. His first Opening Day was on April 8, 1976, as a Yankees second baseman, and that game at Milwaukee's old County Stadium also happened to be the last opener for Hank Aaron.
"I just remember as a young player, being on the field with Hank Aaron," Randolph said. "It was a tremendous honor. He was my hero for years. Just to be in his presence, and I still talk to him to this day, it's a tremendous honor to know him."
As Ojeda and Nelson each put on their old familiar caps amid the trading action, the former said it still gave him a special feeling. It was 30 years ago this season that No. 19 won 18 games and started the fabled Game 6 that Mookie Wilson won for the Mets en route to their last title.
"I'll be honest with you, when you throw a cap on -- we just put these on -- it feels different," Ojeda said. "I've got my baseball cap on -- I don't have to be a former big leaguer, like us. When you throw that cap on, it's kinda cool. The #CapsOn for Opening Day, it's a perfect marriage. I love it. I am not kidding you, I feel different with my hat on."

In 1920, German immigrant Ehrhardt Koch created his own cap company out of the back room of a rented property in Buffalo and the New Era Company was soon formed. Now his great grandson and New Era's CEO, Chris Koch, was admiring lids on everyone as a season dawned again.
"It's been spectacular," Koch said. "We're thrilled to be able to partner up with Major League Baseball for this Opening Day celebration. Just to see the fans on the floor here, and quite frankly seeing all the different posts from all the fans all over the country and the world.
"It's special to me because my family has been in this business since 1934 when we did caps for the Cleveland Indians, the first team. So the whole thing about #CapsOn as part of baseball, and as part of the uniform, and it's always been -- that becomes very personal to me."
Franco said seeing the smiles on the faces of the traders as they buzzed about glory days of the past while prognosticating now made it a special delight to hand out caps and sign autographs. It was another Opening Day, in some ways different and in other ways a familiar old friend.
"It means that summer's coming, that's for sure," Franco said as a chilly rain persisted outside. "It's another great baseball season. Opening Day's always a little nervous -- jitters here and there -- but otherwise it's the start of a new season and no one knows who's going to win and who's going to lose."