Most people pay attention to swimming about once every four years, but when an athlete is dominant and in form it can be a captivating sport. Michael Phelps is in such a place right now - perhaps more than any other competitor ever has been. Not only did he manage to qualify for eight different events at the U.S. Olympic Trials, perhaps the deepest and toughest event in the world outside of the Olympics, but he never lost a single race. He won every single qualifier and meaningless warmup race that he had. He's truly a machine. Not only that, but he will be a favorite, if not the favorite, in all eight of his races in Beijing.

The potential for Phelps to win eight gold medals and break Mark Spitz' 36-year-old record of seven gold medals is captivating for even the most casual sports fan. For sports bettors it's more than that, though. The public is going to be paying close attention to his quest, and the media will cover it to death, so betting volumes are going to be higher on swimming than they probably have any right to be. High betting volumes almost always means that there are opportunities for bettors who are paying attention.

Phelps has one big advantage going into this quest - he's been there before. He'll be swimming in the same eight events that he swam in Athens four years ago. He fell just short of the record then, with six golds and two bronzes. Last year at the World championships Phelps won seven golds, and was only robbed of the eighth when his medley relay team was disqualified. There was little doubt that they would have won if they were able to compete. It's certainly possible. Grant Hackett is an Australian swimmer who is favored to win his third consecutive gold in the 1500-meter freestyle. He is one of many international swimming insiders who have said that Phelps can do it.

The odds in some of Phelps' races are already ridiculous, and the public isn't paying nearly as much attention yet as they will. He's at 1/3 to win the 100m butterfly, 1/12 in the 400m individual medley, 1/8 in the 200m version, 1/20 in the 200 freestyle, and a ridiculous 1/25 in the 200m butterfly. Bodog doesn't have prices set on his three relays yet, but when they do the Americans will be heavily favored there, too. Any astute bettor will quickly see that there is little point in betting on him, and even a parlay is going to have more risk than it is worth. You really need to find another way to get a shot at making some money on his races, then.

Phelps is in top form. The problem is that every other swimmer in the world is aiming to be in their best form in Beijing, too. Phelps will have a gigantic target on his back, and everyone will be looking to be the giant killer. Because Phelps is so heavily favored, the rest of the swimmers in the field will automatically have higher prices on them than they otherwise would. The best way to find value, then, is to figure out if and how Phelps might get beat and try to cash in. The chances of it happening might be low, but the payoff will be significant if it does. That's more attractive to me than betting 100 dollars to win four.

Perhaps his biggest threat will be wearing the same uniform as Phelps. Ryan Lochte was the silver medalist in the 200m IM behind Phelps in Athens, and he has been working hard to close the gap since. He was the second most decorated swimmer behind Phelps at the 2007 worlds. He swam fast enough to break the world record in the 200m IM, his specialty, at the Olympic trials. The only problem is that Phelps swam faster and won the event. Lochte has an intense rivalry with Phelps, just as he does with backstroker Aaron Piersol. He ended Piersol's seven-year winning streak last year, so he is clearly fueled by those rivalries. That will have him at his best in Beijing. Lochte is at 9/2 to win the 400m IM, and a particularly attractive 4/1 to win at 200m.

The only individual event that Phelps didn't win in Athens was the 200m freestyle. He was up against perhaps the greatest swimming field ever assembled in that race. Australia's Ian Thorpe won, and Pieter van den Hoogenband was second. Thorpe has retired, and van den Hoogenband is not at his best anymore, so this race has turned into one of Phelps' easier challenges. He is at 1/20 and no other swimmer is better than 12/1. Phelps would have to work to lose this one. That's the scariest thing about what he is trying to accomplish - the conditions are uncertain. The air quality is going to be bad, the heat intense, and the pool not that familiar. Phelps could be derailed by something completely beyond his control. On top of that, he's going to be under intense media scrutiny, and everyone is going to want a piece of his time and attention. That's another factor that makes him an unattractive bet.

In the end, it comes down to this. I'll be cheering for Phelps to win it all, and I think that he stands a good chance of doing it, but there is absolutely no way that I will put any of my money on him, and I quite possibly will entertain myself during the games by trying to make a buck or two picking spots to bet against him.