But it wasn't as easy for Bamburg as simply playing to the crowd. The Gresham, Ore., native also had to impress five judges, all of them fellow professional riders, handing out scores from a booth high above the stands.

As unique as action sports might seem, skateboarding, BMX and freestyle motocross have much in common with gymnastics, figure skating and diving as judged competitions with the potential for confusion and controversy.

"There's always like one or two [guys] that have questions about it," said Graham Gustin, a FMX judge for four years. "Most of the time, they're not really complaining because they are all our friends and we know all of them."

Bamburg was one of seven riders who qualified for Saturday's finals. He scored 84.47 on his first run and had to take a second run, in which he scored 84.30. Adam Jones was the top qualifier with a score of 90.03.

"Obviously, I want to make the finals," Bamburg said, "but I'm more looking at the crowd, seeing if they're happy with what I did. If people are cheering, then that's what it's all about, and I worry about the score later."

Each sport is different, but Gustin said FMX scores were based on five criteria, starting with how well each rider covered the course and hit as many jumps as possible.

Second is the degree of difficulty and innovation in each trick. Another factor is the range of tricks. Gustin said he didn't want it to become just a back-flip contest; Bamburg only had two other tricks in his runs.

The riders also are scored on the execution of each trick - how far they kicked out their legs or lifted their hands off the bars - as well as whether they landed cleanly.

The last component is an overall impression of each run. The five judges Thursday sat in director's chairs with a keypad in front of them, jotting down notes and calling out tricks to one another.

Unlike gymnastics, there is no starting point value for each trick. Gustin said the first rider has to set a base score against which every subsequent rider is judged.

"Somebody's always going to get mad, somebody's always going to be pissed that they thought they didn't get scored good enough," Jones said. "It's not a situation I'd want to be in. You're the guy that's deciding these guys' paychecks."

Gustin, who has judged at the X Games and Dew Tour, still rides in exhibitions but doesn't do back flips. Among the other four judges were Ronnie Renner and Drake McElroy, who made the finals in Salt Lake City last year.

"It keeps me involved with all the people that are at the top of the sport," Gustin said.

Jones had five backflip combinations in his run and earned praise from Gustin for his execution and creativity. He brought back a trick he hadn't done in years - a turntable - in which he kicked his legs over the bars, then swung them back around to one side as he soared off a jump.

"That's actually been a goal of mine lately is to bring back old, cool stuff that nobody sees any more," said Jones, who lives in Minden, Nev.

Although he qualified third in the skateboard park prelims, Austen Seaholm said judging was always "a little suspect." Asked about knowing the distinction between his score of 81.75 and the top score of 83.75, Seaholm said, "You do, but you don't."

"It's kind of like if you're a big name and you do a decent run, stay on your board, you're still going to make the top [nine]," Seaholm said. "A dude like me, if I mess up, I'm not going to make the cut."

Jimmy Walker landed an opposite flair and a bar spin 540 to earn a 91.17 as the top BMX vert qualifier. He was confident that he had made the top seven after his run but had no idea it would be the leading score.

"To tell you the truth, I don't even care," Walker said. "I don't play scores, I don't play runs. It just happens."

Walker said he always considered judging questionable until he served as a judge himself. Trying to score 20 riders with 20 different styles wasn't as easy as it seemed.

"It's impossible," Walker said. "It's like judging colors. Some people like green, some people like black. I guess it's the flavor, and that's why there's five guys up there."

rsiler@sltrib.com