KANSAS CITY, Mo. >> Nobody seems to know when the tradition of doffing a hat began, though most historians date the practice to the days when bowlers and boaters were in vogue.

Nobody seems to know when the Royals picked up the tradition, either.

At some point this season, though, Kansas City players started tipping their caps whenever an outfielder made a spectacular catch, or shortstop Alcides Escobar and second baseman Omar Infante turned a difficult double play, or third baseman Mike Moustakas snagged a hard line drive.

It was a modest acknowledgment, almost a throwback to another era. But it quickly caught on, becoming one of the iconic images of the Royals’ run to the World Series.

“I think it started about halfway through the year,” said left fielder Alex Gordon, whose jarring catch at the wall in Game 4 of the AL Championship Series not only left him bruised and battered, but also got him a stadium full of hat tips.

While Gordon can’t recall for certain, he thinks that starting pitcher James Shields was the first to do it. It makes sense, too, given how the staff ace has been so instrumental the past two years in turning a losing clubhouse culture into a winning one.

Shields has paid tribute from the mound, and teammates have followed his lead.

“The whole dugout does it now. It’s pretty cool,” Gordon said. “I know it means a lot to the pitchers every time we make a good play, so it’s kind of their way of showing it.”

While the Royals were sweeping their way to the World Series, which begins Tuesday night against the San Francisco Giants, the hat tips became one of those memes that pops up everywhere, from hat-tip hashtags on social media to compilations of spectacular catches on YouTube.

The Angels may have their Rally Monkey, the Cardinals may have their Rally Squirrel, but the Royals have gone decidedly genteel when it comes to their October signature.

“Someone just started that in the dugout and we took it and ran,” first baseman Eric Hosmer said. “This group likes to have fun. It’s just a sign of us enjoying ourselves.”

Like helmet stickers in football, hat tips can be awarded to anyone on the field, even the pitcher. But the majority of the salutes are sent to the outfield, where three-time Gold Glove winner Gordon has teamed with center fielder Lorenzo Cain, right fielder Nori Aoki and speedy super-sub Jarrod Dyson to form a black hole for just about every fly ball.

There is plenty of evidence to suggest they might be the best in baseball.

From the world of advanced statistics comes DRS and UZR, which stand for defensive runs saved and ultimate zone rating. Essentially, both stats try to place a value on a defense’s prowess, and the Royals happened to lead the majors in both categories in the regular season.

Gordon, Cain and Dyson each ranked in the top 10 in DRS individually.

Then there’s the evidence fans can see with their own eyes, the kind that doesn’t require a calculator. The Royals have provided plenty of that this postseason.

In Game 3 of the AL Division Series against the Angels, Cain made a pair of spectacular catches, one climbing about 10 feet up the wall and the other to snag a diving liner. A few innings later, Aoki deftly tracked down a drive to the wall as Cain seemed to leap right over him.

“It seems like there’s five of them out there,” said Royals starter Jason Vargas, who was on the mound that night. “Unbelievable is the best way to describe it.”

Cain made another memorable catch in Game 4 of the ALCS against Baltimore, running impossibly far to track down a fly ball early in the game. Dyson made an impressive catch at the wall later, helping the Royals clinch the series.

Of course, the most memorable catch — heck, the most memorable play — of the series wasn’t made by a Royals outfielder. It happened in Game 3, when Moustakas toppled over a railing and into a dugout suite, only to emerge unscathed and with the ball in his glove — the great defense extending to the Royals crowd.

“Hats off to the fans in the dugout suite, pick him up and put him back on the field,” Hosmer gushed afterward.

“We’ve been doing it all year,” Moustakas said. “There’s still some plays that I’m sitting back like, Wow, I don’t know how Cain got there or how Gordo got there. But it’s almost like you expect them to make those plays.”

When they do, they’ve come to expect a hat tip in return.