In sports, like life, progressive leaps rarely come at a steady pace. They comes in spurts—or rather—waves, like the huge wave rolling through the world of pro surfing right now thanks to a dynamic crop of teenage rookies who are smashing the barriers of aerial surfing with added amplitude, reverse rotations, and a variety of landing techniques. By pushing the degree of difficulty through the roof with their newfangled acrobatic aerials, they’re forcing veterans like 11-time world champion Kelly Slater to adapt, or die. That’s certainly been the case at this week’s Hurley Pro taking place at Lower Trestles in San Clemente, California.

Two of today’s brightest young aerial stars are 19-year-old Hawaiian John John Florence, and 18-year-old Brazilian Gabriel Medina. Both have made an immediate impact since qualifying for the ASP World Tour midway through last season, and a big reason why is their incredible bag of acrobatic moves.

Medina’s aerial assault helped him become the fastest surfer to nab two ASP World Tour wins. He earned both victories in a span of four events, and he sailed past Slater more than once along the way.

One month later, Florence became the youngest surfer to win the prestigious Vans Triple Crown in Hawaii. He hasn’t slowed since. Halfway through the 2012 season Florence is already ranked third in the world, one slot ahead of Slater, which puts the rookie squarely in the race for this year’s world title.

The last time a rookie was in the running for an ASP world title was 1992, way back when guys like Magic, Jordan, and Bird were part of the Olympic Dream Team and Bill Clinton was campaigning for president. That was the year Florence was born. And that was the year Slater, as a 20-year-old rookie, clinched the first of his 11 world titles at Pipeline, right in baby John John’s backyard.

That Slater has been able to fend off numerous waves of rookies in the two decades since then is one of the most remarkable feats in sports. What’s especially impressive is his ability to adapt, and learn the new moves being brought to the forefront.

This year, a 40-year -old Slater will be celebrating the 20th anniversary of his first world title by trying to capture his 12th. And this week, Slater is vying for ASP World Tour win number 50 at Lower Trestles, the same hallowed surf break where he won his first pro contest back in 1990. He’s also vying for his third-straight Hurley Pro title, having already clinched five of them since 2002.

Make no mistake, no athlete has dominated a discipline longer than Slater. Period. That’s why he’s entered the world’s greatest athlete conversation.

But Slater will be the first to tell you he’s got his back against the wall this year. While the rookies are constant threats, they’ve also raised the game of the more pliable veterans, including Aussies Joel Parkinson and two-time world champion Mick Fanning, who are blending the best of the old and new in their approaches.

With more than 20 years separating rookies and veterans on tour the variety of surfing approaches is as diverse as ever, making for one heck of a world title race and some very creative high performance surfing.

Editor’s Note: Kelly Slater clinched his third-straight Hurley Pro on Thursday, defeating Australian Joel Parkinson in the final. In the semifinal he beat current world tour leader Mick Fanning, making this year’s world title race even closer.

Photos: (Top to bottom) 18-year-old Gabriel Medina is the youngest surfer on the ASP tour, but his impact has been immediate and dramatic, much to the delight of surfing fans who hike one mile into San Onofre State park to watch the world’s best surfers perform at Lower Trestles. Of course, nobody draws more fans than 11-time world champion Kelly Slater.