Olympic divers spend years perfecting their dangerous craft, but most of us cheering from the couch know it all comes down to the size of the splash, right?

Turns out there's a bit more to it than that.

As Aussie divers Melissa Wu and Ellie Cole chase glory in the 10-metre platform finals tonight, we've called in three Olympians and an expert judge to help you take apart a dive piece-by-piece.

Once you've got the basics, put your armchair critic skills to the test and see whether you could make it as an Olympic judge.

First, your crash course to the perfect dive

We're focusing on the 10-metre platform event in this story, and dive-wise, we've chosen a fairly common combination: a reverse two-and-a-half somersault tuck.

While splash size does matter, that's just the last in a chain of actions you need to take into account.

So, let's check out the elements the judges will be looking for.

First is the starting position, which is all about posture. The head must be in line with the body, elbows straight and feet together.

The second element is the take-off, which must be bold, high and confident. The diver's head must also stay a safe distance from the board.

The third element is the flight phase. This differs from dive to dive, but the dive we're showing involves a tuck position, where the knees are pulled into the chest. The tuck must be tight.

The fourth element is the entry. The body should be vertical upon entry.

And finally, there's the splash. The aim is for a 'rip entry', which has no splash at all.

Did you get all of that? Now let's raise the stakes and make this a bit real

Here to help you figure it all out is Gillian Brooker (L), the CEO of Diving NSW.

She has more than 30 years' experience in the sport, and was named a diving judge for Paris — her third Olympics.

And our diver is Nikita Hains (R), who competed for Australia at the Tokyo Olympics.

One of Nikita's Olympic dives was the reverse two-and-a-half somersault tuck. It's one of the dives she's more confident in, but even the slightest mistake will cost her points.

We've asked Gillian to help you judge an example of Nikita's dive. In this case, the dives were from the trials held in Sydney before the Tokyo Olympics.

You'll see the dive once in real time and again in slow motion so you can take it all in. 

Gillian will give it a score, but not before we let you take a punt and score it for yourself.

Ready? Here we go.

Remember, we're looking for a strong take-off, good technique in the flight path and a clean, vertical entry.

Did you catch all of that? Let's rewind and take another look in slow-mo.

And this time, let's see what our judge thinks …

"She's got quite a good start position," Gillian says.

"Nikita's got some beautiful posture, looks fantastic."

"Then I'm looking for a good jump and a good distance from the board ...

"She had a reasonably good jump."

"I've made a slight deduction because I felt her hands were towards the upper knees and if she'd held her legs a little bit lower down she could have pulled the tuck in a bit tighter and got a faster rotation."

Nikita comes out of the dive a little bit early.

"She's left the dive slightly short and she's slightly turned her body on the entry, so I've made a deduction there."

And it's not quite a rip entry.

"She did throw up a bit of splash … just a little hollow in the back, so that gives up more splash."

As soon as Nikita disappears under the water, judging stops. 

"Divers are a lot like Houdinis. They do all these tricks under the water to bring the water down and minimise their splash or to look vertical, even if they're not vertical ... we don't take all those things into consideration," Gillian says.

You've just given one score. At the Olympics, you would be one of seven judges giving a score. 

The two highest and lowest scores are forfeited and the remaining three are averaged and multiplied by the dive's degree of difficulty, and that gives the dive's final score.

OK, now that you've got some new judging skills, let's play again

We've kept it simple and given you the same dive, but this time from a different diver. 

This is Olympic veteran Melissa Wu, the kind of diver Gillian says "just has the X-factor".

Melissa began diving at 10, and by 16 was making her Olympic debut in Beijing.

She's now in Paris, taking part in her fifth Olympics — and has qualified for the 10-metre platform final alongside teenage team-mate Ellie Cole.

For your benefit, Melissa is performing the same dive, a reverse two-and-a-half somersault tuck. But this time — just like a real judge — you won't have the benefit of reviewing it in slow-mo. So watch closely!

What you want to remember with this dive is the tighter the tuck, the faster the rotation, which should give enough time to lengthen out for a vertical entry.

OK, let's take a look at Melissa's dive…

"She's ticked all the boxes," Gillian says.

"It's a beautiful shape, that tuck shape … then she just times that entry to perfection and just disappears in the water with very little splash.

"For a diver to get a 10 you feel it; I get goosebumps when a diver does the dive for 10.

"To me it was just that tiny little bit scoopy at the bottom."

Want to play one more time? 

This time our diver is Sam Fricker, who made his Olympic debut in Tokyo. These days he's a commentator at the Paris Olympics. 

In this scoring round we’re going to mix things up even more and give you a completely different style of dive: a back armstand double somersault one-and-a-half twist.

Judging this type of dive begins the moment the diver's feet leave the platform to press up into the armstand.

They have to remain as steady as possible. Any sign of a wobble can lead to a deduction.

This dive also requires a pike position in the flight path.

In a pike, the legs have to be straight and pulled into the chest.

Keeping a steady balance while standing on your hands on the edge of a 10-metre platform, as the adrenaline courses through your body, is no easy feat.

Let's see how Sam goes …

"He's come up confidently [into the armstand], he hasn't hesitated," Gillian says.

"I just would like to see him hold that a little bit longer and not wobble as much. And when he pushed off, he pushed too far out, instead of up."

Wu's rocky path to her fifth Olympics

While you sit back in comfort casting judgement, bear in mind these athletes are repeatedly hitting the water at speeds of 60kph.

Wu has now been an Olympic diver for half her lifetime, having made her Olympic debut at the Beijing Games in 2008 at the age of 16.

In the lead-up to the Paris Olympics, she had to limit training due to a chain reaction of injuries, including bulging discs in her neck and knee trouble. She relied on visualisation as a training technique that skips the impact.

Globally, only eight other divers have managed to appear in five Olympics.

This time around, Wu is the veteran, and will compete in the 10m final alongside Sydney teenager Ellie Cole, who has always idolised her.

Wu and Cole will take part in the 10m platform final from 11pm AEST tonight. And you can put your new judging skills to the test too.

• Note: This story was first published in 2021 during the Tokyo Olympics. It's been updated and revived for the Paris Games.

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