What sets Sally Pearson apart from her Olympic hurdle rivals?
With a record-breaking run of 12.35 seconds in the Olympic Stadium on Tuesday night, Sally Pearson finally - and fittingly - joined fellow Australians Shirley Strickland, Maureen Caird and Debbie Flintoff-King as an Olympic hurdles gold medallist.
Pearson, the pre-eminent sprint hurdler of the last two years, was once again a fluid study in technique and speed. But what exactly sets her apart from her rivals?
"To become a good hurdler you require three key skills: basic speed, excellent flexibility and extreme elastic strength," says Colin Jackson, former 110m hurdles world champion and now part of the BBC's athletics team. "Sally has all of those in abundance.
"We know from her performances over the flat 100m that she is a top sprinter; her flat speed is better than anyone else in the race.
"Her flexibility is specific to the hurdles. She is not just loose: she has a great range of movement specifically where it is necessary for her event.
"In technical terms, she has what we call a great split over the barrier. It means that she is in a strong position to run off every hurdle - she can get that front leg down quickly and run off it."
Pearson in full flight has variously been described as a stone skimmed across a lake, or water in a stream flowing over boulders.
Like all great hurdlers she appears not to so much jump into each hurdle as float over them.
"As a hurdler you want to spend as little time in the air as possible," explains Jackson.
"You can only generate speed when you hit the floor. And when you are as technically efficient as Sally you can get closer to the hurdle before jumping and so clear it faster.
"If you watch the hips of a top sprinter from the head-on camera, you will notice that their hips do not sink at all - they stay at the same level all the way through the race.
"The trick is to keep your centre of gravity equal, just as you would if you were a flat sprinter. That's why you dip your head forward when you jump, so that you're not leaning backwards when you land.
"If you look at bronze medallist Kellie Wells, her torso twists as she clears each hurdle. You should always aim to keep your shoulders straight - you don't want any rotation.
"When you get over the barrier, get your arm out straight and then straight back. When Kellie's arm comes back it is way out wide, and that costs her one hundredth of a second at every hurdle.
"Sally's trail leg is also superb. That's the key one because it's the foot an athlete takes off on, and it's the first stride on landing.
"You actually have to be more aggressive with your trail leg than your lead leg, because that is the one that allows you to drive off the barrier."
Pearson has been coached by Sharon Hannon since she was spotted at a Little Athletics state championships in Townsville, Queensland, way back in 1999.
Her training regime is so brutal that she admits, after certain sessions: "I actually felt like I was going to die."
"As a young athlete Sally was always good to the first four or five hurdles," says Jackson.
"What she was worked on with Sharon was her technical endurance - the skill that allows an athlete to keep their speed over the barriers for the entire race, rather than just the first half of it.
"So Sally will train over 12 hurdles, rather than the normal ten.
"In her training she has to combine the speed of a sprinter with the lightness of a long jumper. If she puts on too much muscle bulk she will get faster but have too much to carry over the barrier, so she will do lots of plyometric work - jumping, leaping, bounding.
"In the gym, that equates to lifting weights like a jumper - not to put on mass, but to develop elastic strength. So she will do power-cleans, bench presses, squats and lots and lots of circuits."
Not since Cathy Freeman in Sydney 12 years ago had Pearson's home country invested so much hope in an athlete. "There is a page of Olympic history waiting for her name," declared The Australian newspaper, around the time she was packing her bags for London.
There was also an unhappy omen hanging over her on the blocks: no woman has ever won the sprint hurdles title at the World Championships and then followed it with Olympic gold the following year.
Pearson, nerveless, dealt with it all. And key to that was another of her trademark explosive starts.
"She attacks the 100m hurdles like it was 100m flat," says Jackson.
"She runs at the first hurdle like it's not there, which sounds strange but is actually the dream position to be in.
"Those first three hurdles are your acceleration phase, when you go from zero to close to your top speed. You do not want to be putting the brakes on there.
"Athletes without her mental confidence would come out of the blocks with six hard strides and then eight more which are 'approach' strides - leaning back, getting ready for the barriers.
"All that slows you down. From hurdles three to seven, the barriers are coming at you rapidly.
"You are just on auto-pilot. But if you are working well technically you will keep attacking the hurdles, and you will carry that speed all the way to the line."
Pearson took gold from reigning champion Dawn Harper by just 0.02 seconds. It was no fluke.