An Audi zigzagging all over the back of a Mercedes at the front of the field with little more than an hour to go certainly made for great TV. But even my limited maths had allowed me to work out that this was a phoney battle.

I knew the Mercedes wasn't going to win the Spa 24 Hours last weekend and had been confident - almost little too confident, as it turned out - of that fact for the better part of four hours. And I wasn't very happy about it.

The growing tide of sporting restrictions in the Endurance Cup rounds of the Blancpain GT Series rendered the Auto Sport Promotion Mercedes team impotent in the final stages of last weekend's Belgian classic. These limitations on tactical freedom left it unable to respond to the challenge from the Sainteloc Audi team in any way at all.

Strategy is limited in the BGTS enduros by a 65-minute maximum stint length and by the pitstop window regulations that effectively mandate that each car spends the same - or a similar - amount of time in the pits. Together they stifle the strategic diversity that to my mind distinguishes endurance racing from many other forms of motorsport.

A maximum stint length measured in time is a simple solution to a difficult problem created by wildly different fuel consumption figures in the GT3 arena. Some cars just use a lot more fuel than others. And the 'anyone can play' philosophy of the GT3 class will mean that is always likely to be the case. Don't forget, the speed of GT3 cars is equated not by the rulebook, but by the Balance of Performance.

I concede that it was tighter than I thought for the #90 ASP Mercedes. Working out if a car can go to the finish in a succession of 65-minute runs is not an exact science. A stint can end up being 64 minutes and 50-something seconds, or it might be little more than 62 minutes, given that a dry lap at Spa takes about 2m20s.

ASP boss Jerome Policand revealed after the race that his lead car had been on course to enter the pits after a stint of 64 minutes and 56 seconds at one point late in the race. That didn't leave much of a margin for error and explains why he overruled the car's engineer to bring the car in a lap early.

ASP was left with no tools in the box to try to shake things up when it realised it was on the back foot

The ASP Mercedes actually fell 37s short. That's how long Raffaele Marciello - the big star of last weekend's race - had to be held in the pits at the car's final pitstop to make sure he didn't go over the 65 minutes on the run to the chequered flag. That had the result of dropping the car to third position behind the factory Sainteloc Audi R8 LMS and the #8 M-Sport Bentley Continental GT3.

The pitstop window was introduced at the beginning of last year to halt to the arms race in the pits. The top teams were spending big to try to bring down the time their cars spent stationary.

There are two times mandated in the rules: a lower maximum and an upper minimum. (That's not a contradiction, honest!) This year, cars had either to leave the pits before 95s had elapsed after crossing the entry line or wait until after 133s were up.

The lower time reflects the occasional need for a wheel to be changed after a puncture, or perhaps a piece of damaged bodywork to be taped up. But a higher bottom mark last year also enabled a full tank of fuel to be added.

A reduction of the lower time from 115 to 95s last weekend precluded that. And with it went the ability of the teams to try to gain an advantage by double-stinting a set of tyres.

The rationale was simple and not without merit. Some cars were not capable of getting two stints out of a set of the latest Pirelli tyre, even during the cooler conditions of the night. Actually, that was probably most cars apart from the Mercedes-AMG GT3. Had the organisers left the lower time unchanged, the front-engined Mercedes would have been handed a massive advantage.

That's not to say that tactical thinking is entirely dead in the BGTS enduros. ASP owed its position at the front of the field last weekend to a super-aggressive strategy that required bringing the #90 Mercedes into the pits just about every time there was a caution of any kind.

ASP even managed double stints of sorts. Three times after protracted safety car running, it didn't change tyres. There was enough fuel left in the tank to get enough gas in for the car to complete the better part of an hour.

You could argue that this gameplan came back to haunt the team at the end of the race, and that every strategy has its cons as well as its pros. But my quibble is that ASP was left with no tools in the box to try to shake things up when it realised it was on the back foot as the race dew to its conclusion.

And it needed to do that if it was going to make a race of it. As good as it might have looked on TV, I would argue that a race is not exciting if you know who is going to win.

Another problem last weekend arose from the technical pitstop rule. The reasons behind its introduction for Spa last season were similar to the change to the pitstop window for this year. There was a real fear that the second-generation Audi R8 LMS that entered customer hands in 2016 would be able to go through the race without a change of brakes - unlike all its competitors.

Sportscars, as a discipline, has always rewarded the best teams with the quickest mechanics on the wheel guns and the cleverest strategists

Every car now must stop for five minutes, which is used to fit new sets of pads and discs. Last year, the technical pitstop had to be taken before the 22-hour mark. This year, the rules stipulated that it must be taken between the start of the 12th hour and the end of the 15th.

The problem was that the rule penalised championship regulars going for points. Double points are awarded at Spa and the second tranche are handed out based on the results at the 12-hour mark.

That's about the time a team might be thinking of doing the brakes. So, when it started to rain early in the 12th hour there were a raft of pitters. They included the winning Sainteloc Audi, the #90 ASP Mercedes and the two factory WRT Audis. They did not include the #8 Bentley. Its drivers, Maxime Soulet, Andy Soucek and Vincent Abril, arrived at Spa in the lead of the Endurance Cup championship and were intent on leaving with it, too.

How can it be that the rulebook favours teams not competing for the championship? That's clearly an oversight to my mind.

That can be easily rectified, I think, but the problems created by the 65-minute stint maximum and the pitstop window are much harder to solve.

The organisers must know the fuel consumption of the cars and they can control the amount of fuel that goes into the cars and at what rate. So why not give allow each car enough fuel to go a certain number of laps between stops, but with the option to stretch it if necessary?

Remember that some of sportscar racing's greats - Tom Kristensen and Bob Wollek spring to mind - routinely went a lap further around the eight and half miles of the Circuit de la Sarthe than their team-mates. Getting the most mileage out of a tank of gas is surely one of the great skills of a sportscar driver.

The prowess of crew members in the pits should also be an essential part of the game. Sportscars, as a discipline, has always rewarded the best teams with the quickest mechanics on the wheel guns and the cleverest strategists on the laptops (or pencil and paper in days of old, I guess).

I understand why the tentacles of the BoP have spread into the sporting rulebook with the stint maximum, the pitstop window and the technical pitstop. I even concede that they have the intended effect of helping to ensure close racing and preventing someone from stealing an advantage.

I just contend that such rules they are out of kilter with sportscar racing in general and the traditions of a great endurance event like Spa in particular.