Could anyone at the start of the season, way back in March in Australia, have envisaged we would have three drivers separated by seven points with just 71 laps of the 2.677-mile Interlagos circuit remaining. As the F1 circus flocked to the track on the outskirts of Sao Paulo, all three drivers . . . McLaren-Mercedes duo Lewis Hamilton and Fernando Alonso, plus Ferrari ace Kimi Raikkonen . . . know the final 190 miles will determine their destiny.

Many suspected at the start of the year that this might turn into something of a classic season, but that anticipation revolved round the expected battle between old rivals Alonso and Raikkonen. However, the word 'old' has taken on a new emphasis.

Double world champ Alonso is 26 years old while Finn Raikkonen celebrated his 28th birthday this week. Hamilton of course, the young rookie who has re-written the history books this year, is a just-out-of-nappies 22.

And it is this baby-faced assassin who heads into the nailbiting conclusion to the season with a four-point lead over his Spanish teammate, and a further three ahead of the Ferrari No 1. But while Hamilton will start the race as favourite to become the youngest world champ ever . . . and the first to win it in his rookie season . . . there are, as you would expect, a whole catalogue of permutations which could see any of the three drivers crowned when the chequered flag falls.

The simplest, of course, is for Hamilton to win the race. Do that and no matter what the other two achieve, the title and all the riches which accompany it are his. Somehow though, life . . . and especially Formula One . . . is rarely that simple.

Should all three cars fail to finish . . . the most unlikely scenario . . . Hamilton would be champ.

If Alonso wins, the young Englishman would need to finish second . . . a tough ask at a circuit which has so recently been dominated by Ferrari . . . since by finishing third he would only be tied on points with the Spaniard who would lift the title by dint of having won five grands prix this year to Hamilton's four.

Should, as many expect, Raikkonen win the race, the Iceman would lift his first championship in his first year with the Italian giant if Alonso finished no higher than third and Hamilton could manage no higher than sixth.

Fair to say then that nerves will be fraught once the race starts.

And, of course, it's not just the drivers who will feel the strain. Every member of the individual driver's pit-crew will be under the most intense pressure. Imagine the scenario.

You're the man with the responsibility for undoing the nut on the front left wheel for Brazilian race leader Hamilton.

He enters his pitbox at 40mph; stops; you remove the nut from the old tyre/wheel but, just as the new wheel is placed on the car, the nut slips out of the pneumatic airgun in your hands. In slow motion it bounces down by your knee; you go to grab it; miss it; grab again; place it in the gun; fire the gun into the centre hub on the wheel; the car drops down off its stands and Hamilton is back off racing.

But that fumble has cost the Englishman six seconds. More than that, it's cost him . . . and the rest of the team . . . the championship.

Responsibilities don't come much higher.

And while those tensions would be high for any championship-deciding race, at the end of what has been one of the most politically charged and controversial seasons, the blood pressure is likely to be off the scale.

Remember, this is the end of a season which has seen a top secret 740-page Ferrari dossier found in possession of McLaren's chief designer Mike Coughlan, secreted to him by ex-Ferrari chief engineer Nigel Stepney.

The fallout from that landed McLaren with a $50 million fine, a barrowload of suspicion and an exclusion from the Constructors' World Championship, the title team boss Ron Dennis covets more than the drivers' title.

On top of that, there has been the ongoing feud between Alonso and Hamilton. Irrespective of what public face the Spaniard has tried to put on over the past few days, he remains bitter and hurt that despite being a double world champ he was given identical equipment and information as that which Hamilton received. That the English youngster then proved blindingly quick and refused to roll over for Alonso further incensed his team-mate. That, of course, came to a head in Hungary where the Spaniard sat petulantly in his grid box refusing to allow Hamilton in to change his tyres ahead of his final qualifying run. Since then the McLaren camp has not been a happy place to be.

With two wins in the last three races in Belgium and China, Raikkonen lines up favourite to win the race at a circuit where his Ferrari team-mate Felipe Massa won comfortably last year. Team orders, despite what the FIA, the sport's governing body, argues, will come into play. Should Massa be leading towards the end with Raikkonen second, Ferrari will instruct the positions to be swapped.

Massa's other role will be to make life as uncomfortable as legally possible for the two McLarens. Should Raikkonen lead from the start, the Brazilian's role will to slow the two silver cars as much as he can.

"We both want to finish the race and decide the championship fairly, " Hamilton said yesterday. "We've fought hard . . . very hard at times . . . this season, but both Fernando and I want the decider to be above board and decided by driving ability. But having said that, it's going to be a hell of a race." A hell of a race certainly, and the world can't wait.