LONDON The Olympic show jumping contest that will start this weekend and wrap up next week is a story of extremes, with some of the youngest riders at the Games going head-to-head with some of the most seasoned.
In youth's corner is Reed Kessler, who just turned 18 last month and will be both the youngest rider at the Games and the youngest ever chosen for the U.S. equestrian team. She will ride Cylana, the horse she qualified on.
"Cylana was super in our warm up- we just jumped a few jumps and she feels ready for tomorrow!" Kessler Tweeted on Friday.
And while Ian Millar, 65, may not be the oldest rider - that distinction goes to 71-year-old dressage competitor Hiroshi Hoketsu of Japan - he definitely boasts the most Olympic mileage. His 10 Olympic appearances are a record for any sport.
What fascinates Millar most about being in the game (and Games) for so long is how jumping has evolved over the decades.
"It's really not the same thing at all as it was in 1972," he said. "It's a different type of horse we're using. The style of riding is quite evolved. The whole way the courses are built, the materials used - it's virtually unrecognizable."
"So it's been a very interesting challenge for me to stay with that change."
He didn't rule out participating in the 2016 Rio Olympics, saying if horse Star Power was up for it, he was too.
With a mixture of age and experience among the riders and a large number of young horses in the field, the contest for team and individual Olympic gold could prove unpredictable.
A number of nations could have a shot, unlike dressage and eventing where Germany and Great Britain were pegged at the outset as the teams to beat.
"I think there's probably eight or nine nations that could win at any time," said British chef d'equipe Rob Hoekstra.
"The Americans and the Canadians sort of stand out as non-Top League nations that could do well. Obviously the Germans are always a threat. The French are strong, the Swiss are strong, the Dutch are strong."
The Top League refers to the FEI Nations Cup series, in which Germany, France and Britain currently are ranked one, two, three. However, this year's series did not include all nations, so it is an imperfect predictor.
Among individuals, bookmakers Ladbrokes rate Britain's Nick Skelton, a six-time Olympian, and mount Big Star joint favorites with U.S. veteran Richard Fellers on Flexible.
"I can understand why," Skelton said of his 5:1 odds.
"The horse has been great all season. It doesn't bother me. It won't make any more pressure than there already is. The thing is I'm sat on a very, very good horse. And I'd rather be favorite than a rank outsider anyway."
Defending Olympic champion Eric Lamaze of Canada, riding the unseasoned Derly Chin de Muze, is seen as an outsider at 20:1.
Lamaze suffered a shattering blow last year when his gold medal horse Hickstead collapsed and died in the arena at a World Cup event in Verona.
He said losing such a great horse made him question whether to go on. But after soul-searching and encouragement from the owners of his horses, he decided to persevere.
"For me with the tragedy that happened last year with Hickstead, I'm not really coming to these games with the feeling that I'm defending my title," the Canadian team captain said.
"Hickstead would have been still in great shape, I'm sure. And having him here would have really felt like I was defending my title. Having said that, I came here with a very, very good young horse, we have a great team and we're going to try our very best."
Team mate and first-time Olympian Tiffany Foster has had a long road to the London Games after breaking her back when schooling a young horse four years ago.
But she said on Thursday that she is on form and excited.
Canada's equestrian squad had a rough start to the Games and was knocked out of contention before the team finals in both eventing and dressage.
But the Canadian jumpers, who had their best Olympics showing ever in 2008 when they won individual gold and team silver, hope to recoup some national honor.
"I feel very good," Lemaze said of the team's chances.
The event starts on Saturday with a first qualifier for the individual final. All 75 riders complete one round, which also determines jumping order for the team final.
The team final is set for Sunday and Monday. There are two rounds with the top 10 teams of four competing in the second. The three best team scores are added to calculate the total score of each team.
On August 8, the 35 horse-rider pairings with the lowest cumulative scores go through to the individual final. This again is two rounds, with the best 20 riders in the first jumping in the second and a jump-off to break ties.
However, each nation is only allowed to field three riders, whether they are on the team or competing as individuals.
(Reporting by Sarah Edmonds; For all the latest Olympic news go to here)