That’s what happened at the Infineon Raceway this weekend. The Rolex Series event featured close competition among Daytona Prototypes and a late yellow that bunched the field, which gave Alex Gurney his chance to slip past David Donohue. Alas, according to reporters for motorsport.com at the track, there were precious few fans — especially compared to Sunday’s turnout for the IRL race.

The California contest posed the age-old dilemma for the Rolex Series. The racing’s fine, but where are the fans?

From my perspective at Mosport in Canada, where I was covering the American Le Mans Series race, there couldn’t have been a better case scenario for my annual “State of Sports Car Racing in North America” address.

At Mosport’s ninth round of the American Le Mans Series, on qualifying day they were piling into the infield and lining the outside fences in the rain in anticipation of the duel between Audi’s diesels versus Porsche’s Spyders. They also turned out to see Ron Fellows, the “Mayor of Mosport,” at his home track. On Sunday, sunshine brought an even bigger crowd — one of the best Canada’s classic circuit has seen for a sports car race.

As a veteran of endurance racing wars, it suits me fine that between the Rolex Series and the ALMS there are 26 races on this year’s schedule for prototypes, including events in Mexico and Canada. In addition to keeping traditional circuits funded better than they might be otherwise, the schedule enables many people to be gainfully employed in road racing who could care less about ovals or NASCAR.

But what about the attendance conumdrum? Compared to the ALMS, the Rolex Series has had more prototypes since the early days of its Daytona Prototypes. The series sanctioned by the Grand American Road Racing Association and owned by the France family has re-built the prestige of the Daytona 24-hour due to star-studded entry list. Tracks such as the Infineon circuit at Sears Point, the Autodromo Hermanos Rodriguez in Mexico City and Watkins Glen anchor a decent schedule.

No wonder Rolex Series driver Max Angelelli asked me recently at Daytona: “Why are there fewer cars in the ALMS and more fans?”

It seems to me the cars in the ALMS match up better with the expectations of that the persistent category of fans who love endurance racing. The prototypes’ performance in the ALMS is far more harrowing and palpable than the Daytona Prototypes due to greater technical sophistication. While the DP’s are old-fashioned in construction and apperance, the ALMS is pushing the envelope with diesel-powered V-12 turbo Audis and Porsche Spyders with the most sophisticated suspensions this side of a lunar landing vehicle.

By contrast, can fans identify with a Red Bull-sponsored Riley chassis powered by a Porsche engine versus the Gainsco-sponsored Riley chassis powered by a Pontiac? Even if they’re ably driven by the current generation of the Donohue and Gurney clans?

The Rolex Series is attempting to improve its formula by running separate races for the relatively numerous prototypes — cutting back on cautions from collision with GT entries and eliminating the complications of multi-class racing for fans. Given the template-like cars and single-category approach, the Rolex is moving closer to the sports car equivalent of NASCAR, not a surprising development since the ownership of those two series is the same.

Again, the ALMS matches up better with sports car tradition — the one that families apparently pass down to their children — which began early in the 20th Century at the Le Mans 24-hour. The format features the inevitably exciting prospect of prototypes whistling past GT cars, leveraging the fans’ appreciation for car performance and guaranteeing an interesting day at almost any corner. At the end of the day, a good time is had by all even if the best prototype smokes the competition. (I pause here to note that last year’s race at Mosport and the most recent race on this year’s schedule at Road America were decided by less than two seconds.)

When it comes to the GT’s, the Rolex features tube-frame, purpose-built cars. They’re easy for a manufacturer to brand, easy for a speciality manufacturer to produce and inexpensive for a team to field. You can also run a turnkey racing Porsche off the assembly line.

Once again, car count does not seem to be the most important calling card. The ALMS’s traditional formula of up-rated road cars like the Corvette and production-based cars like the 911-based Porsche RSR, Ferrari F430 GT Berlinetta and Panoz Esperante seem to have more appeal to fans who can buy and drive these cars to and from the track. (The Corvettes may not have any competition in the GT1 class, but this matters not to all those fans driving their Corvettes in the pre-race parade at Mosport.)

That is precisely the formula that ALMS founder Don Panoz touted after licensing the Le Mans name and rulebook. It doesn’t hurt that the French race is now in the forefront of the green movement with purebred racing cars like the Audi R10 TDI and Peugeot’s new V-12 diesel. This improvement of the breed is a development which even has Formula 1 administrators scratching their heads.

Given that the fan turnout to see the high-tech entries that also run at Le Mans has been quite good despite Audi’s dominance in past seasons, the arrival of competition from the Penske Porsche Spyders has obviously upped the pace at the turnstiles. Joint weekends with Champ Car at Road America and Long Beach (where the Rolex failed miserably with too many cautions in 2006) have also proven quite successful at the gate for the ALMS, which added two events to this year’s schedule including next week’s race in Detroit.

The addition of the Dyson Racing Porsches, Honda’s Acuras and two Creation entries have brought the ALMS to 13 prototypes for the Mosport weekend (versus 18 Daytona Prototypes at Infineon). The word on the street has additions to the ALMS in both the bigger LMP1 category and the LMP2 that are likely to mean at least 15 prototypes next year, maybe more. The ALMS is thus gaining on car count as well as fan count.

According to Rolex Series owner Jim France, racing series are built from the paddock out (hence the low-cost technology of the Daytona Prototypes). If that’s true, then both the ALMS and Rolex are quite healthy.

All too often, I’m not even sure the casual racing fan really knows the difference between these series. In any event, take a flyer, get out and see a race based on the world’s greatest endurance events at Daytona or Le Mans. If you live in North America, there’s sure to be one happening somewhere near you in the years ahead.