Sporting code crackers

Jarryd Hayne's successful transition from rugby league to American football has not surprised his US agent. Photo / AP

Jarryd Hayne's NFL exploits prompted Michael Burgess and Andrew Alderson to recall other code-swappers.

Jarryd Hayne's progress as a San Francisco 49er has been remarkable - but there is probably one man in the United States saying "I told you so".

Back when many thought Hayne's NFL dream was a flight of fancy, his American agent Jack Betcha had faith in his ability.

Agents can often be full of hyperbole but Betcha's foresight has so far been on the money.

"When I first saw him competing and practising, it looked like this had been done before," he told the Herald on Sunday in March.

"You wouldn't have known he had just walked in from Australia. Watching him catch and move and even punt - it all looked very natural. The skillset is already in place and I have no doubts he is going to make it."

Betcha has managed more than 150 players in his career, including several first-round draft picks, but had no doubt Hayne is a special one.

"I don't need Jarryd but I wanted to work with him," Betcha said. "He has a powerful presence. You can feel the determination flowing through him and he has an X-factor that will serve him well."

Hayne's future at the 49ers will be decided by September 3, when their final 53-man roster is named.

Below we look at other examples of transition athletes with determination and X-factor who adapted to their new sports with differing levels of success.

Rob Waddell

Rob Waddell won Olympic gold in 2000. Photo / Getty Images

As the Sydney Olympic single sculls champion, Waddell had the perfect rowing physique. Then he switched careers to grind for Team New Zealand in the America's Cup, turning his arms, legs and chest into a form that would have impressed inhabitants from the mists of the Ugandan jungle. He repeated the recipe before and after the Beijing Games.

Jim Thorpe

Jim Thorpe at the 1912 Olympics. Photo / Kenny Rodger

Thorpe reverted between professional baseball and American football before adding gold medal-winning pentathlon and decathlon performances at the 1912 Stockholm Olympics. King Gustav of Sweden presented one medal saying, "You, sir, are the greatest athlete in the world", to which Thorpe replied, "Thanks, King". He lost his medals after the revelation he'd played minor league baseball, breaking the Olympics' strict amateur ethos. The gongs were reinstated 29 years after he died in poverty.

Madonna Harris and Chris Nicholson

Madonna Harris. Photo / Kenny Rodger

This pair remain New Zealand's only summer/winter dual Olympians.

As outlined in Joseph Romanos' Our Olympic Century, Harris left for the US in 1978, having already been selected at national level in the 400m hurdles and basketball. Ten years later she competed at the Winter Olympics in the 20km cross-country skiing at Calgary and then Barcelona summer Games in cycling's road race. She has since entered endurance horse racing events such as the Mongol Derby.

Nicholson finished 10th in cycling's 100km team time trial at Barcelona before turning his skills to speed skating, where he achieved a fourth-placed finish in the 5000m team relay and 17th in the individual 1000m at Albertville in 1992. He also represented New Zealand at the next Games at Lillehammer.

Kayla McAlister

Kayla McAllister. Photo / Getty Images

The former Mystics netballer has enjoyed a remarkable rise in rugby sevens. She switched in 2012, encouraged by the Olympic opportunities. Despite her brother Luke's rugby prowess - he played 30 tests for the All Blacks - McAlister admitted she had limited understanding of the rules and techniques. But she has thrived and was named sevens World Player of the Year in 2013.

Manfred Moore

Moore had played running back for the San Francisco 49ers, Tampa Bay Buccaneers and Oakland Raiders - winning the 1978 Super Bowl with the Raiders - when he was lured to Australia to play rugby league for the Newtown Jets. The idea was the brainchild of Jets' flamboyant supporter John Singleton - an advertising mogul and horse racing millionaire - and their former coach Jack Gibson. Moore scored a try on debut, accompanied by an avalanche of publicity, and thrilled the crowd by throwing a football over the grandstand and out of the ground in a halftime stunt. He played only four more first-grade games before returning to the NFL with the Minnesota Vikings.

Darren Bennett

Darren Bennett excelled in the AFL and NFL. Photo / Getty Images

Bennett was on his honeymoon in the United States in 1993 when he called the San Diego Chargers, asking for a tryout. A former AFL forward with the West Coast Eagles and Melbourne Demons, he was known for his long range goal kicking but injuries accelerated his retirement in 1993. He made his Chargers debut in 1995 and became one of the standout punters in the league, named in the NFL's all decade team for the 1990s. Bennett played 159 NFL games over 11 seasons and is credited with introducing the AFL style drop punt (now common) into American football.