Basically they hijacked the Cubs' shtick and one-upped them in their own house.
Cubs' reliever Mike Montgomery theorized the D-Backs' relievers had rehearsed for months, knowing it would catch the Cubs unaware.
It was a pre-emptive strike that shocked and awed the Cubs' pen.
"That's crazy man," Montgomery said. "I'll tell you those Diamondback guys had it planned and they nailed it. We weren't expecting it to be anything. It was funny though. They had some good stuff.
"We might have to plan something now and be ready for a rain delay. We weren't planned. Those guys were like 'I can't wait to get to Chicago and have a rain delay so we can do these little skits we made.' That's what it felt like to me."
Pedro Strop called the D-Backs' routines "awesome," though Carl Edwards Jr. wasn't quite as impressed.
"They did pretty good," Edwards said. "But we didn't try. We just kind of did whatever. I feel like every time we have a rain delay there's going to be a team that tries (to beat them).
"It's just fun, the way we're interacting and not close to each other. We really don't care about the viral part. Just having fun. What should we do? Just sit there? Or we could have a dance-off."
If we've learned anything from the YouTube era, it's the more people laughing with you, the more views you get. The Cubs' Twitter account counts on the bullpen for laughs, and clicks.
And once you've started something as click-worthy as a dance-off, it's hard to go back.
The bullpens were moved from the field to underneath the bleachers this year to add more seats and avoid potential injuries. That means the relievers are out of sight, though in-house cameras are on them at all times and the dance-offs frequently appear on the video board in left.
There doesn't seem to be any real dancers among the bunch of relievers and coaches. Some appear to be doing a version of the "Charlie Brown" dance, just bobbing their heads up and down with slumped shoulders and their arms hanging down.
Whatever it is, it seems to work.
Imagine if they had Twitter and YouTube back in the summer of 1969 when the Cubs were still in first place, pre-collapse. Pitcher Dick Selma, egged on by manager Leo Durocher, had a routine in which he jumped up and down in the bullpen waving a towel in the air to get bleacherites involved, while third baseman Ron Santo leaped up in the air and clicked his heels after Cubs' wins at Wrigley.
"That's my thing," Santo said. "I'm kicking the habit, the losing habit. It's my salute to the Bleacher Bums. I'm working on a double kick for the World Series."
After the Mets came back to win the final two games of a July series at Wrigley, star Tom Seaver yelled in the clubhouse: "Who saw Santo's victory dance today? Let's hear it for Leo!"
Long story short: The 1969 Cubs didn't make it to the World Series.
Unlike the '69 Cubs, the current Cubs' relievers don't want to be seen as rubbing it in on their opponents. They only dance after Cubs' home runs before the sixth inning, and not if it's a lop-sided game.
It's a "loose" atmosphere, newly added reliever Justin Wilson said, and it doesn't interfere with the job at hand.
"Everyone is a grownup down there," Wilson said. "You go down and do what you want, as long as you're ready when your name is called."
Wilson said "knew a little" about the dancing Cubs when he was with the Tigers.
"I saw it at some point, but I didn't expect to have to do it ... until I was a Cub," he said.
Hector Rondon is the ringleader, and he was the one who ordered some masks for that Aug. 3 game against the Diamondbacks. Wilson, who was given a unicorn mask to wear, admitted he has no dances moves to speak of, and confirmed "Dancing With the Stars" was not in his future.
"I just went for it," Wilson said. "I couldn't tell you what I did."
Edwards is the most creative, and performed pantomime fishing routine in which Wilson was the fish he hooked.
Mostly they perform together, but when Rob Zastryzny was called up from Triple-Iowa he did a solo dance that appeared to be a combination of an Irish jig and the "Elaine" dance from "Seinfeld."
"I don't know what he was doing," Edwards said. "I asked him what he called it. Stiff. That's 'Rob Z' though."
Zastryzny was sent back to Iowa without pitching an inning, but manager Joe Maddon lauded his call-up, saying Rob Z "improved his dancing skills dramatically."
Japanese pitcher Koji Uehara supposedly was reluctant to participate because that type of celebrating during a game is frowned upon back in Japan. But Strop and Rondon both said Uehara, now on the disabled list, is a happy convert.
"He likes it," Rondon said. "Sometimes he jumps up when someone hits a homer. The only person who never dances is (Wade) Davis. He told me the other day 'Maybe I'll start dancing too.' "
As the closer, Davis doesn't go out to the bullpen until the late innings, when the dancing has stopped. He's said he would do it someday, but that day has not arrived.
Will other teams' bullpens come into Wrigley now and try and top the Cubs, as the D-Backs did?
Do the Cubs now have to think up some more creative stuff?
"I don't know," Rondon said. "Probably we need to start winning first and after that we probably get into the dancing routines, more choreography. We talk about it a little, but first we have to win the games."
Whatever happens from here on out, don't expect it to spread to the dugout. Kris Bryant was asked if he had any moves he could bust.
"I'd rather hit the home runs than get in the dance contests," Bryant said. "I'm by no means a dancer, but that (dance-off) was great, and the D-Backs had a couple really good skits, too. But they had enough time to think about it, too. Those rain delays were brutal."
Brutal, but funny.