How did Ferrari make that strategy mistake with Alonso?

The championship is over, the title is decided in Sebastian Vettel's favour but the nagging question everyone is wrestling with tonight is, how did Ferrari get its tactics so wrong?

We have seen often this season how strategy can win races, but today we saw it lose a championship. Of course no championship is won or lost on one race, but when a driver has an eight point lead and needs only a top four finish, it can cost a championship if you get it wrong.

Fernando Alonso started the race in third position, needed only to finish fourth and yet the team contrived to lose him positions so he ended up seventh. It meant that Vettel beat him to the championship by four points.

Ferrari team principal Stefano Domenicali tonight declined to go into details of how the decision to pit Alonso on lap 15 was arrived at. He did however give us an inkling of the considerations.

"We made a wrong decision in terms of strategy for three reasons: we marked a rival with two cars (Alonso and Massa), we were unduly concerned about the wear rate of the soft tyres and we did not take into consideration the difficulty of getting past other cars on the track."

The reason they made the mistake was because they were too concerned with what Mark Webber was doing and failed to see the bigger picture.

Webber radioed in to say that his tyres were losing performance and on lap 12 he pitted for new hard tyres. He rejoined behind the Toro Rosso of Jaime Alguersuari, who held him up for two laps losing him almost two seconds.

Before the race, there was concern about how long the soft tyres would last before they started to degrade. Based in data from Friday and Saturday practice, there were concerns that they might start to go off quite quickly.

Seeing Webber in difficulty as early as lap 11/12 clearly made Ferrari worry about how long Alonso's tyres would go. But it was the same for everyone and Alonso was arguably in the best shape at this point, lapping in the high 1m 45s range, which was the fastest of the leading cars.

At this stage he had a lead of just 10 seconds over Robert Kubica in the Renault, who had started the race on hard tyres and would therefore clearly be running long. Right behind him was Adrian Sutil, likewise on a hard tyre strategy. But more significantly Alonso had a lead of just 16 seconds over Nico Rosberg, who had pitted under the Lap 1 safety car and 19 seconds lead over Renault's Vitaly Petrov, who had done the same.

A pit stop at Yas Marina Circuit takes around 22 seconds, so by coming in on lap 15 as Alonso did, he was inevitably going to drop behind these cars. And in the case of Rosberg and Petrov, they were not going to stop again.

Now to the point about underestimating how hard it would be to overtake the Renault in particular. In qualifying, Petrov was the third fastest car through the speed trap at 316km/h. Alonso was able to do just 312km/h on the straight. So it was always going to be difficult, The Renault F Duct is among the most efficient in the field. In addition, last season proved how hard it is to overtake on this circuit.

To be fair to Ferrari, Red Bull has put Webber on strategies which require him to pass cars, such as Singapore, which is hardly the easiest place to overtake, but they really underestimated Petrov and his Renault's speed.

Much has been made of the fact that Renault supplies engines to Red Bull so he would be particularly obstructive, but I think Petrov was driving for himself and for his own career tonight. He will have done his prospects no harm at all with this drive.

Alonso could afford to have only three cars finish in front of him, which is what he had on lap 14 and with this move he invited another four to move ahead, two of whom would not be stopping.

It's surely not possible that Ferrari could simply have failed to realise Rosberg and Petrov's positions. Like all teams they have a highly paid strategy person, who has a sophisticated computer to give advice. He would then propose a strategy to Andrea Stell, Alonso's engineer and to Chris Dyer, who is in charge of operations.

The tyres were going through a graining phase at this time; Vettel's pace had dropped off into the 1m 46s. But then the tyres came back in and the pace picked up again.

Perhaps as they thought about whether to stop Alonso they were concerned that if the tyres should start to go off they would be vulnerable to Webber and the cars that had stopped and therefore must have reasoned that Vettel, Hamilton and Button would face the same threat, so they too would be behind the cars who had stopped.

But they pulled the trigger too soon. Massa pitted on lap 13 and failed to contain Webber, he rejoined two seconds behind. So they called in Alonso to cover Webber and his world championship went up in smoke. It didn't help that his in lap and out lap were 1.5 seconds slower than his rivals.

Had they left him out, he would have stayed behind Button, who went on to do 39 laps on his soft tyres. Alonso would probably not have been able to do that many laps, but he would have been able to pit around the time Hamilton stopped on lap 22/23 and rejoin ahead of Rosberg (just), in a net fourth place once the hard tyre runners stopped. Instead, stuck behind Petrov for 39 laps he lost time and track positions.