The UBS Race Strategy Briefing is written by James Allen with input and data from several F1 team strategists and from Pirelli

Jenson Button’s victory in the 2012 FORMULA 1 SHELL BELGIAN GRAND PRIX makes him the leading points scorer of the last three races, a reversal of a trend, which began in May, where the British driver and his McLaren team lost their way.

The problem Button was suffering from lack of performance due to mismatched tyre temperatures between the front and rear tyres and the team was experimenting with various ways of solving that, including heating the tyres from the inside, using heat soak from the brakes.

They’ve now found a solution, partly involving aerodynamics to increase rear end grip and aerodynamic balance, but also mechanical set-up and the result has been 51 points in three races. His performance in Belgium showed that he not only got the tyres working well in qualifying to take pole position, but also was able to comfortably do the race with only one tyre stop. His second stint, on the hard compound Pirelli tyre, was almost 170km, the longest that McLaren has done on a single set of tyres in 2012.

Pre-Race expectations

The build up to this race was dominated by the heavy rain on Friday, which meant that the teams learned nothing about long run tyre performance. They were shooting in the dark on Sunday, after a handful of dry laps on Saturday morning, where they were also preparing for qualifying. It left little time for drivers to establish how to get the tyres to work.

Also part of the strategy in Spa was deciding whether to go for a low down force set up, with less wing, to help straight line speed in sectors one and three, or whether to go for more down force to help with sector two. Gearing was also important and several drivers found themselves with a less than ideal combination of gearing and down force, with the result that they were hitting the rev limiter on the Kemmel Straight and losing speed.

All of this led to a mixed up grid with two Saubers and a Williams at the front, Red Bull struggling for pace, with Vettel in 10^th place and Hamilton down in seventh.

Pre-race the feeling was that a one stop strategy would be around 5 seconds faster than two, but it would leave the driver vulnerable at the end of the race to cars on fresher tyres. McLaren were certainly thinking of one stop for Button starting from pole, circumstances permitting, while most of the others were planning two stops, especially as the track temperature started rising before the start.

The start line accident changed the strategy in two ways; by eliminating four competitive cars, it changed expectations of what many drivers might get from the race and it brought out a safety car. This slowed the field down and meant that the first four laps of the race, which are normally the hardest on the tyres as the car is at its heaviest, were relatively easy.

This encouraged a number of drivers and teams to change plans and try to do one stop. Among them were Williams and Mercedes, which is surprising, because they have been among the hardest car on the tyres in race conditions this season. It didn’t work out for them or Williams, thanks to a late puncture, which robbed Senna of 8^th place. It did however work for Red Bull’s Sebastian Vettel.

He was helped by qualifying outside the top ten so he was able to start the race on a new set of medium tyres, whereas his front running rivals were all on used mediums at the start, from qualifying. This small detail was important to the outcome for Vettel, who was able to get to lap 21 on his first set of tyres, which meant he needed to do 23 laps on a new set of hards in the second stint.

Button enjoys a margin

Jenson Button was able to make the most of the largest performance margin over other cars we have seen this season so far. The McLaren’s underlying car pace was around half a second faster than its nearest rival at Spa and Button was able to exploit that fully in qualifying and the race.

He could do one stop relatively easily, helped by the crash, which eliminated rivals, also by the safety car and by the freedom to run at the front in clear air. Being able to control the pace, not have to defend from other cars meant he could focus exclusively on managing the tyres and this meant Button had complete control all afternoon.

The challenge from Lotus did not materialise as not only did the Lotus not have the expected race pace, but also it seemed to struggle to get temperature into the tyres. This was evident at the restart where Hulkenberg jumped Raikkonen. Lotus was on a two-stop strategy and without the pace to exploit that fully, there was no challenge for the win from Raikkonen.

Button even had sufficient margin in the final 15 laps to make a precautionary second stop and still win the race, but he had the pace and liked the balance of the car on the tyres he had. He was still lapping in the 1m 54s in the last few laps, a similar pace to the Lotus on tyres which were 8 laps newer.

Vettel managed the race skilfully too, using the one stop plan and the pace of the Red Bull on hard tyres to jump the two stoppers and move up from 10^th on the grid to 2^nd. It’s debatable whether that would have worked if the four front running cars had not been eliminated at the start, but despite losing two places at the start, to cross the line 12^th at the end of lap 1, Red Bull adapted well to the changing circumstances and Vettel drove a very positive race, making several important overtakes to ensure his progress.

Schumacher loses a strong result

Schumacher drove very well on Sunday, making some excellent passes and defending robustly, as is his style.

Could Schumacher have finished ahead of Hulkenberg in fourth place if he had done a similar two stop strategy, rather than change tactics after the safety car and switch to a one stopper?

The German ace got past Hulkenberg on lap 13, when Hulkenberg pitted Schumacher was on new medium tyres and ran a 19 lap first stint, which left him 25 laps to do on a set of hards. It was a big ask, but by staying out past lap 13 or 14 he was committed to stopping just once.

Schumacher was ahead after Hulkenberg’s second stop on lap 27. But he only had four seconds advantage and 17 laps to go to the finish on the same set of tyres, ahead of a similar pace car on fresh tyres. It was never going to work. The Mercedes was relatively fast on full tanks, but as we have seen often this year, the competitiveness didn’t continue as the car got lighter and the tyre wear increased. Schumacher was forced to make an unscheduled stop for tyres on lap 35 and lost three positions.

Had he pitted on a similar pattern to Hulkenberg and stayed on a planned two stop, he would have fought him for the fourth position, but possibly would have lost out due to the Mercedes pace fading on lighter tanks. Nevertheless the failed one stop bid cost him places to Massa and Webber and he ended up seventh.

Belgian GP Tyre Choices

M=Medium; H=Hard; N=New; U= Used; DNF=Did Not Finish

The UBS Race Strategy Report is written by James Allen with input and data from several F1 team strategists and from Pirelli.