Dressage: What is it, and why are Great Britain so good?

Any sport to prominently feature Phil Collins in an Olympic final is deserving of further scrutiny.

Great Britain have two Olympic dressage gold medals to their name as London 2012's equestrian events come to a close.

GB won the team title at Greenwich Park on Tuesday then Charlotte Dujardin saw off a host of rivals, two of whom employed a medley of Phil's finest numbers, in Thursday's individual final, in which horses perform seven-minute routines to music.

These achievements are great, these hours the finest the sport in the UK has known. But these are also events utterly beyond the comprehension of a good many onlookers.

What is it, exactly, that GB are now double Olympic champions in? What did they have to do to win? How do judges decide? And why Phil Collins?

What's the aim of dressage?

"Think of it like ballet, gymnastics and ballroom dancing combined," suggests Judy Harvey, respected rider and trainer as well as BBC commentator at London 2012.

"The rider is the man taking the lead, the horse is the partner in time with the music. The riders are trying to achieve the spectacular but make it look easy and smooth, in total harmony."

In other words, dressage is about guiding your horse through a series of moves inside a rectangular arena and getting it to perform those moves in the best-looking way possible.

The idea is that riders demonstrate an understanding with their horse. Harmony, as quoted by Harvey, is a word so central to the sport that it's part of the scoring system.

That might sound a bit fuzzy to people who are used to their sport being hard and fast: in football, you can be as discordant as you like but if you win 1-0, you win 1-0.

But dressage is akin to many other Olympic sports - gymnastics, diving, figure skating at the Winter Games - in being subjectively judged, rewarding interpretations and artistry.

How do you win?

Judges sit at various points around the rectangle, scoring each move as they see it from that angle.

When you see Dujardin get a score like 90.089, which is what she scored for individual gold, that comes from taking all the artistic and technical scores awarded by each judge, then averaging them. It's a percentage, 100 being the maximum, though scores over 90 are incredibly rare.

"The scoring is broken down into sections," explains Pippa Funnell, one of Britain's leading eventers [eventing being a three-discipline equestrian sport which includes dressage, as well as cross-country and showjumping].

"Rhythm, energy and elasticity is one set, then harmony between horse and rider, then choreography and use of the arena, then degree of difficulty."

Half of the score is down to artistry, and half is based on technical aspects of the routine.

What you should be looking for in terms of the technical score, and what the judges reward, is the way the horse carries itself: does it look the way it should look for each move? This extends right down to the tiniest things like the position of its neck and whether its mouth is open or closed.

You also have to watch for communication between horse and rider. Does it look effortless? Do they look like they are performing together, or fighting each other?

What made Charlotte Dujardin the best?

There were two outstanding rides in Thursday's final: Dujardin for Britain and, just before her, Adelinde Cornelissen for the Netherlands, who scored 88.196 for silver.

Dutch dressage fans will tell you Cornelissen deserved to win and that Dujardin won because of home advantage, namely the crowd influencing the judges. It was a tight contest.

"Charlotte's horse Valegro has a faultless outline, by which I mean there's no tension in the horse," is Harvey's view of the showdown between the two. "The neck is very important, as is the way the horse carries the bit in its mouth.

"Adelinde's horse Parzival gets a bit tight in its neck, whereas Charlotte's horse had a beautiful curve from the front of its withers [the area between the shoulder-blades] up to its ears."

Stephen Clarke is the president of the judging panel, contributing one-seventh of the marks for both riders. The judges award their scores independently, so they don't know who has won until they see the total scores averaged out, at the same time as the audience.

"Our impression was Adelinde's horse had huge power and expression but for us there needed to be a little more lightness," was Clarke's summary. He added that Cornelissen lost a few marks for harmony along the way.

"Charlotte had more [harmony] but maybe not as much power and expression today. They ended up very close. I'm sure lots of people will have different opinions but our decision was for the harmony.

"When we finish the test and send our marks, I've no idea which one is going to come out where. When Charlotte finished, I didn't really know which one would win, Charlotte or Adelinde. They were both fantastic."

Why is Phil Collins involved?

Not all dressage events feature music but the individual Olympic finale, known as the Grand Prix Freestyle, traditionally does.

The music sets the tempo for a routine and if you can make your performance work really well to a certain piece, then that can only help your artistry marks.

Dujardin asked Tom Hunt, a composer well known within the sport for his dressage works, to put together a sequence of rousing British themes that featured The Great Escape and Land of Hope and Glory among others. It did the job. "We talked about using some patriotic music on home ground, and Tom did a fantastic job," said her mum, Jane.

But Phil? Well, if you can get the rights to use his music and think it helps, then it's your choice. Tears for Fears and Billy Idol were other entries, some of which said more about the music taste of the nation in question than they did about the rider's dressage skills.

Austria and Denmark were two of the nations to compete to Phil Collins hits but, against all odds, Dujardin and Valegro can dance into the light.