Purists have been licking their lips anticipating that the Ironman 70.3 World Championship finally had a true test to find the best swim, bike and run at the half Ironman distance. Beset by 100-plus temperatures, the rugged hills on the bike and run courses at Lake Las Vegas should indeed avoid large packs on the bike and demand a true three-tool champion.

Still, despite moving this race to a month before Kona, a schedule adjustment that invites serious Kona challengers to use this race as a final tune up for the big one, many cautious Ironman stars are leery of what might be asked of their bodies on this tough course. And so the likes of Andreas Raelert, Marino Vanhoenacker, Rasmus Henning, Chris Lieto and Tim O’Donnell among the men and Chrissie Wellington, Kelly Williamson, Yvonne Van Vlerken and Mirinda Carfrae are passing on the diminishing allure of the $18,000 first prize available this weekend.

With the injury to the dominant, defending champion Michael Raelert, the men’s race is seemingly up for grabs and no clear obvious favorite has emerged.

The women’s contest is quite different. While the field is more exclusive and this smaller due to qualifying standards, there are at least 10 women who have a clear argument to be named the favorite. Addicted to newcomers, dark horses and long shots, this prognosticator picks a refugee from the politics of international track and field as his choice to take down the proven excellence of Julie Dibens, Mary Beth Ellis, Catriona Morrison, Karin Thuerig, Leanda Cave, Angela Naeth, Jodie Swallow and Magali Tisseyre.

The following contenders are offered in order of the author's belief in their chances.

Melissa Rollison, 27, Australia

In 2011, a star is born in women’s 70.3 racing.

Rollison, a former Australian steeplechase national record holder and top 5,000 meter runner who had grown weary of track and field, hit the sport of triathlon like a comet with three straight 70.3 victories at Muncie, Vineman and Steelhead that put her right among the favorites for the Ironman 70.3 World Championship podium at Lake Las Vegas. Why go overboard on the late to triathlon newcomer? At Muncie, Rollison set a race record and topped 70.3 heavyweights Kelly Williamson by 3:31 and Leanda Cave by 3:47. While Cave out biked her by 2:12, Rollison’s 1:19:19 outran certified speedster Williamson by 63 seconds and Cave by a lot more. At Vineman 70.3, Rollison set a women’s course record of 4:09:00 which was 6:14 better than Cave and 8:49 better than Mirinda Carfrae. Cave out-biked by Cave by just 35 seconds and Rollison out biked Mirinda Carfrae by 5:51. On the run, Rollison’s 1:16:28 outran the 70.3 gold standard runner Carfrae by 2:49. In case you thought Rollison was a flash in the pan, she ran 1:16:33 (5:58 better than runner-up Heather Jackson) and biked 2:18:06 (gave back 1:57 to Jackson) to win Steelhead 70.3 by 3:56. The former champion high school swimmer can swim within two minutes of Cave and equal to Carfrae. Can she bike? Trains on hills of Boulder and has been within two minutes of top level women 70.3 cyclists in this year’s three big outings. Was she any good a year ago? Finished 2nd to Caroline Steffen at the Asia Pacific 70.3 Championship at Laguna Phuket when she really was unknown and untested.

Julie Dibens, 36, Great Britain

The two-time winner at Abu Dhabi, the 2009 Ironman 70.3 World Champ, the 3rd place finisher in her debut at Ironman Hawaii, the 2009 slayer of Chrissie Wellington at Boulder 5430 two years ago, has had a decent 2011 -- 1st at Ironman Coeur d’Alene in race record 9:16:40, 1st at New Orleans 70.3, Rev 3 Quassy, and 2nd at Rev3 Knoxville.
The hilly bike course at Las Vegas should suit her. But not so much more than Rollison.

Mary Beth Ellis, 34, United States

Ellis entered star territory with her 2nd place finishes at the Ironman 70.3 World Championship in 2008 and 2009. But after signing on with super coach Brett Sutton a year ago, Ellis has had a superstar summer with wins at Ironman Regensburg in mid-June, became the third–fastest woman Ironman competitor with an 8:43:34 at Ironman Austria in early July, and rounded things off in late August by breaking Erin Baker’s 21-year-old race record with a 9:03:13 at Ironman Canada. Do we think that Ellis’s Hillary Biscay-style appetite for heaping platefuls of Ironman will ruins her speed? Her 4:21:06 win at Singapore 70.3 seems to indicate no. Is her bike good enough to cope with the likes of Karin Thuerig on Lake Las Vegas hills? Ellis’ 4:48 at Austria and 4:54 at Canada and a summer of working out with Sutton’s crew on Switzerland’s hills indicate won’t be blown away.

Karin Thuerig, 39, Switzerland

This tall former schoolgirl volleyball star became a two-time cycling time trial world champion and two-time Olympic cycling time trial bronze medalist. Through all her career, she has been Switzerland’s second greatest long distance duathlon and triathlon star behind Natascha Badmann. Evidence includes two ITU long distance duathlon World Championships, two Powerman Zofingen duathlon world titles and in triathlon Ironman titles at France in 2002, Switzerland in 2005 and 2010, and Lanzarote in 2006. For Thuerig, the half Ironman is a sprint, and she won the Monaco half in 2006 to prove she could do it. So what has she done in multisport lately as her cycling career is winding down? She was 3rd at Galveston 70.3 with a killer 2:12:24 bike split and a creditable 1:23:46 run. At Austria 70.3, she beat Erika Csomor by 4 minutes and Yvonne Van Vlerken by six minutes. Hot water and wetsuits forbidden will likely doom the slow-swimming Thuerig’s chances of winning at Las Vegas, but the hills on the bike will supercharge her bike advantage and as a winner at Zofingen’s rugged hilly run course she can finish strong.

Leanda Cave 34, Great Britain

No one races as many long course events so well. In 2011, Cave was 2nd at Vineman 70.3, 3rd at Muncie 70.3, 1st at Wildflower and Rev 3 Knoxville, 2nd at Escape From Alcatraz and Kansas 70.3, 1st at the Desert Classic Duathlon and 6th at Abu Dhabi. In 2010, she finished off a season in which she won two 70.s with a 10th at Kona, a 2nd at Ironman 70.3 Worlds and a 3rd at Ironman Arizona. Whew.

Magali Tisseyre, 29, Canada

Perhaps the most reliable, all around women’s 70.3 performer. This year she was 3rd at Rev3 Knoxville, Wildflower long course and Ironman 70.3 Oceanside; 4th at Ironman 70.3 San Juan. Last year, Tisseyre was 3rd at the Ironman 70.3 Worlds in Clearwater, 2nd at Augusta 70.3, 1st at the Vancouver half, Buffalo Springs 70.3, Mooseman 70.3 and 3rd at Ironman 70.3 Florida. Best bet for the podium, not so good odds for the win.

Jodie Swallow, 30, Great Britain

The defending Ironman 70.3 World Champ who lives and trains much of the year on Switzerland’s steep mountain roads should be the favorite to repeat. However, an acutely painful and exacerbating nagging foot injury caused her to abandon Ironman St. George after arriving in T2 with a 12 minute lead. Same sad story at Challenge Copenhagen when she finished the bike in a dead heat with fellow Team TBB teammate Rebekah Keat and had to pull out again. However, all hope of recuperation is not lost. Lisa Norden could barely walk before her off form London World Championship series performance – but one month later she took home the $151,500 check at Hy-Vee.

Tenille Hoogland, 33, Canada

Hoogland had a professional breakthrough in 2010 with wins at the San Francisco Triathlon at Treasure Island and the San Francisco Triathlon at Alcatraz. But she proved she belonged among the elites in 2011 with a win at Calgary 70.3, a 4th at Wildflower long course and a 3rd at Eagleman 70.3.

Heather Jackson, 27, United States

Started 2011 with a bang, losing am electrifying duel to the finish line at Oceanside to none other than reigning Ironman World Champion and 2007 Ironman 70.3 World Champion Mirinda Carfrae. Backed it up with a 6th at New Orleans 70.3, a 5th at Rev 3 Quassy, 4th at Boise 70.3, and a 2nd at Steelhead 70.3. In 2010, Jackson took 5th at Ironman 70.3 Worlds, 2nd at Steelhead, 3rd at Timberman and Boise 70.3s.

Lesley Paterson, 30, lives in San Diego, represents Great Britain

In 2011, Paterson won Mooseman 70.3, the Orange County International Triathlon and the XTERRA Pacific Championship, placed 4th at St. Croix 70.3 and won the Scottish 10-mile Running Championship. In 2010, she was 6th at Ironman 70.3 Worlds, 2nd pro woman at XTERRA USA Nationals, and 2nd Pro Woman at Oceanside 70.3. In 2009, this film writer and producer took 2nd at XTERRA Worlds.

Linsey Corbin, 30, United States

This Ironman and multiple Ironman 70.3 champion -- and 5th place finisher at Kona – had a so-so 2011 with an 8th at Oceanside 70.3 and 4th at Ironman 70.3 New Orleans.

Melanie McQuaid, 38, Canada

Three-time XERRA World Champion continues to improve on pavement with a 3rd at Mooseman 70.3 and a 2nd at Ironman 70.3 Lake Stevens this year to go with her many XTERRA regional championships.

THE MEN

Andy Potts, 34, United States

Potts has been almost unbeatable in 2011, with 70.3 wins at Oceanside, Florida, and Vineman and Olympic-scope triumphs at Capital of Texas, Philadelphia, Escape From, Alcatraz and Chicago. The only flaws to be found in Potts’ season have been a 2nd at Life Time Fitness Minneapolis and an off-form 11th at Hy-Vee last weekend.

Joe Gambles, 29, Australia

Gambles had a 5th in 2009 and 4th in 2010 at the Ironman 70.3 World Championship on a flat course in Clearwater. Can he score on a tougher course? He has a 2nd at Wildflower and a course record win at Vineman 70.3 and a course record win at Ironman Wisconsin that says he can.

Filip Ospaly, 35, Czech Republic

Despite some small injuries this year, the 2010 Ironman 70.3 World Championship silver medalist who dueled Michael Raelert to the end has wins at St. Anthony’s and Ironman 70.3 Austria, a 2nd place finish at Ironman 70.3 Wiesbaden, a 3rd at Chicago and a 7th at Hy-Vee. Ospaly, a three-time Olympian, a three-time ITU World Cup winner and a Life Time Fitness/Toyotas Cup series champion, goes way back – to a 4th at ITU Worlds in Cancun, a 1st at the 2001 European Championship, and 2nd places at the 2002 Lausanne and 2005 Hamburg World Cups.

Craig Alexander, 38, Australia

Alexander, the 2005 Life Time Fitness champion, the 2006 Ironman 70,3 World Champion, the 2008 and 2009 Ironman World Champion, once went three and one half years without losing a 70.3 race. Unfortunately, am energy sapping virus he contracted this spring in Sydney slowed him down for months. But a course record 8:19 at Ironman Coeur d’Alene with a 2:46 run shows he’s still got the mojo. While he is using this race as a Kona tune up after a disappointing 4th last year, does he have enough of his old speed to take the Lake Las Vegas prize?

Chris Lieto, 39, United States

If the Chris Lieto who decimated the field at Mermorial Hermann Ironman Texas this year and was a brave and impressive 2nd at Ironman Hawaii in 2009 shows up, he should be a co-favorite at the very least. If the Chris Lieto who in 2011 was 5th at Miami 5150, 3rd at Kemah, DNF'd after leading to T2 at Ironman Texas, was 2nd at Hawaii 70.3, and 7th at Vineman 70.3, this prediction stands. Here's hoping this guess is dead wrong, Lieto is at his best, and he brings the Ironman 70.3 title back to the USA.

Raynard Tissink, 37, South Africa

Tissink now has eight Ironman titles to his credit. And after a career-best 5th at Kona last October, the third of his top 10 finishes there, Tissink is setting PRs at the Iron distance. Does he have enough speed to contest with the fast boys at Las Vegas? Smart money says the hills on the bike and run make this a strength course – right up Tissink’s alley.

Paul Matthews, 28, Australia

Matthews has been very busy and very consistent in 2011. He took 3rd in New Orleans, 1st at Kansas City, 1st at the DC 5150, 4th at Rev 3 Quassy, 2nd at Boulder Peak, 2nd at Vineman 70.3, 3rd at Chicago and, most impressive, 4th against the incredibly superb and deep field at Hy-Vee.

Matt Reed, 35, United States

Reed has had a very up and down season as he prepares for his first assault at Kona. But he hasn’t been too distracted to score some typical Boom Boom Reed performances along the way, including 2nds at St. Anthony’s and Philadelphia, a win at Life Time Fitness Minneapolis and a 2nd at Steelhead 70.3.

Luke Bell, 32, Australia

Bell won 70.3s at Lake Stevens and Hawaii, took 2nd at St. Croix 70.3 just 16 seconds behind Maxim Kriat, and was 3rd at Ironman Texas and Kansas 70.3.

Michael Weiss, 30, Austria

Weiss has had a good 2011 including a 3rd at Oceanside 70.3, 4th at Nautica South Beach, 2nd at Ironman 70.3 Austria and a 7:57:39 2nd place at Ironman Austria.

Tim Berkel, 27, Australia

Recent second straight win at Challenge Copenhagen accompanied by a win at Busselton 70.3, 2nds at Racine 70.3 and Port Macquarie 70.3 and a 3rd at Challenge Cairns.

Paul Ambrose, 27, Australia

Ambrose has had a very good 2011 with a win at Racine 70.3, 2nds at Mooseman 70.3, Rhode Island 70.3 and Lake Stevens 70.3, a 3rd at Boulder 70.3, a 4th at Boise 70.3 and 6th place finishes at California 70.3 and Ironman St. George.

James Cunnama, 28, South Africa

Very consistent in 2011 with a win at Rev 3 Quassy, 2nds at the Columbia Triathlon, Ironman 70.3 Singapore and Ironman 70.3 South Africa and 3rds at Wildflower long course and Ironman South Africa. This backed up a strong 2010 which included wins at Ironman Florida, Ironman 70.3 Austin, Rev 4 cedar Point, and the Alpe d’Huez Triathlon.

Ben Hoffman, 28, United States

Hoffman has been coming on strong the last two years with a 2nd at Ironman Lake Placid and 4th at Ironman St. George and wins at Muncie 70.3 and Boise 70.3 in 2011. In 2010, Hoffman won Ironman Lake Placid and Branson 70.3 and took 2nd at Boise 70.3 and 3rd at Buffalo Springs.

Luke McKenzie, 29, Australia

This year his best finish was 3rd at Ironman 70.3 San Juan and looks ready for a return to top form he enjoyed the past two years. In 2010 he scored wins at Ironman Brazil, Ironman China and the Busselton half. In 2009, he won Ironman Japan, Ironman Malaysia and Ironman Western Australia.

Jesse Thomas, 30, USA

After his breakthrough win at Wildflower, the former Stanford record holder at the 3000 meter steeplechase filled out his first full season as a triathlon professional with a 5th at Kemah, 4th at Escape From Alcatraz, 5th at Boise 70.3 4th at Rev 3 Portland. He also scored fastest runs at Portland and Vineman 70.3

Matty White, Australia

In the past year, White scored 2nds at Challenge Cairns, Busselton 70.3, Ironman Western Australia and Ironman 70.3 Yeppoon. He won’t break through with a win at Lake Las Vegas, but will score soon at a smaller event.

Fraser Cartmell, 29, Great Britain

Last week, Cartmell’s hopes were high when he came off the bike 3rd at big money Hy-Vee – but stomach woes on the run wiped out his chances at a big payday. In 2010, he won Ironman 70.3 UK and Ironman 70.3 South Africa.

Fredrik Croneborg, 30, Sweden

Hasn’t done much in 2011, just a 4th at Korea 70.3. His 2010 season was better – 1st at Ironman 70.3 China, 2nd at Ironman 70.3 Japan and 3rd at Ironman 70.3 Philippines.