It happens time and time again in a Formula One race. A driver will catch up to the guy in front and then sit behind him for lap after lap.

Overtaking moves are rare in Formula One and more often than not happen during the pit stop sequences. That's not to say a driver can't pass another out on the track -- Juan Pablo Montoya proved that with his stunning overtaking move on Michael Schumacher in the European Grand Prix. But you also get situations like the Canadian Grand Prix where Michael Schumacher, Ralf Schumacher, Montoya and Fernando Alonso ran nose to tail and nobody was able to pass anybody.

"The deal is that those cars are so competitive and so close together that it is simply too close a competition to get the chance of overtaking," Michael Schumacher said afterwards.

But there is more to it than that. In Canada, Montoya (who did pass Alonso to move from fourth to third) quickly made up the 12-second gap to Ralf Schumacher and then got bogged down. These days in F1, when you get close to a car in front it takes away the air your car needs for aerodynamic downforce and your car becomes skittish.

After the Canadian race some people said that Ralf simply wasn't aggressive enough in trying to pass Michael. Both brothers denied the charges.

Aerodynamics are the main problem as today's F1 cars rely far more on aerodynamic downforce and grip than on mechanical downforce and grip.

Using drafting, or slipstreaming as they call it in F1, to pass a car in front is extremely difficult because today's F1 cars are so aerodynamically efficient that they don't punch a big hole in the air for the car behind to take advantage of.

"A lot of the regulation changes over the last few years have actually hindered the ability to race," David Coulthard said. "These cars are narrower than they used to be, and you get less drag following that car, and so you get less of a tow. Wider cars with bigger wings created a bigger hole in the air, and when you got into that hole in the air you got sucked along.

	Montoya, near, is passed by Michael Schumacher at the 2003 Brazilian Grand Prix in April.

"When I first came into F1 you could pass someone from 10 car lengths behind. The tow was so good. Now you come out a of a corner two car lengths behind, and you sit there because the efficiency of the wings is such that the air comes off the rear wing and down immediately, so you don't get the tow."

A car can be two seconds a lap quicker than another in qualifying but still struggles to pass it in the race. It would take more than a few minor modifications to the technical rules to change that.

"A tweak of any rule won't do the trick," said West McLaren Mercedes director Ron Dennis. "You can't un-invent performance. If you know how to make a car slippery, then you make it slippery, and the end result is a very clean air flow coming off a car that doesn't create the sort of towing capabilities that existed in the past."

These days it takes most of the straight for one car to use the draft to catch up to the car in front. The fact that about 70 horsepower covers three-quarters of the field doesn't make it any easier. Trying to out brake the guy in front of you is equally difficult because the braking zone is so short these days because the carbon fiber brakes have such stopping power.

"It would be nicer for us to really race against each other," Kimi Raikkonen said. "Now even if you are like seven km/h (4.5 mph) quicker on the straight you are not going to pass because the straights are not long enough. It always takes a long time to catch up. After about half the straight you start to gain, but then it is too late. And you brake so late that overtaking is not going to happen."

Outdated track design plays a major role in the lack of passing. But that is a whole other issue. Going back to the technical and car side of it, Coulthard says going back to steel brake discs won't solve the problem because you still can't get close enough to the car in front due to the aerodynamics.

"People talk about increasing the braking distances by going to steel brakes," Coulthard said. "It will make no difference if we brake at 200 meters or 100 meters because it is how close you can get (to the car in front.) I hate to say run a Handford wing that makes the air messy, but that type of thing would create more of a hole in the air. But it would make the car so inefficient that it would not be F1 anymore."

	"	The deal is that those cars are so competitive and so close together that it is simply too close a competition to get the chance of overtaking. "
		— Michael Schumacher

Changes should be made to the rules but not to the point where they destroy the essence of F1. People don't want F1 to become like a basketball game where the lead changes every five seconds.

"I don't think that overtaking should be an easy thing," Montoya said. "Overtaking is a challenge, and you need to find your way past people and you have to push them to make mistakes and take advantage of that."

Coulthard cautions against any attempts to artificially upset the balance of competition.

"In a soccer game if the score is zero-zero you don't keep taking men off from one side until some one scores a goal," he said. "That is just the way it goes sometimes. It is sport. It is unpredictable and sometimes you won't always get the big result that everybody is looking for. The public isn't stupid. We know when we are seeing something real and when we are seeing something contrived."

While there hasn't been a lot of passes for the lead, this F1 season has been one of the best in years with six different winners in 10 races.

But many people think something should be done to increase the chances of overtaking. F1 fans don't want to see 70 passes for the lead in one lap. But one passing move in 70 laps might be nice.

Dan Knutson covers Formula One for ESPN and ESPN.com.