The intense title battle between Lewis Hamilton and Nico Rosberg continues at the Belgian Grand Prix this weekend, as the Formula One championship resumes following a summer break with Rosberg leading his Mercedes teammate by just 11 points.
Rosberg is looking to win his maiden F1 title but Hamilton, the 2008 F1 champion, has increased the pressure with some excellent driving in recent races and shown that he is a threat from anywhere on the grid after some mishaps in qualifying. The Mercedes pair have won nine of 11 races so far: with Hamilton edging Rosberg 5-4 in wins.
Here are five things to know ahead of Friday's first practice session:
___
FRESH START?
If anyone needed a summer holiday it was Sebastian Vettel.
The four-time defending champion will want to forget the first part of the season, where he regularly trailed his less illustrious Red Bull teammate, Daniel Ricciardo.
Vettel secured only two podium positions, no pole positions, and retired from three races. Ricciardo has won two GPs since making the offseason switch from Toro Rosso and the Australian has generally outwitted Vettel, much to the surprise of most observers.
Vettel sits in sixth place overall, 43 points behind Ricciardo, who is third.
Some contrast to last season, when Vettel had won four races by this stage as he coasted to a fourth straight title.
His victory at last year's Spa GP triggered off an astonishing run of nine straight wins. But the way things are going now even one seems far off.
___
TEENAGE AMBITION
Most teenagers will be sitting in a classroom worrying about exams looking on horizon when Max Verstappen makes his Formula One debut next season.
The 16-year-old Verstappen has been chosen by Toro Rosso — Red Bull's junior team — to replace Frenchman Jean-Eric Vergne in 2015 and will race alongside Russian Daniil Kvyat.
He insists he can handle the pressure of racing against experienced adults.
"Ever since I was seven years old, Formula One has been my career goal," Verstappen said. "I think the age doesn't really matter. In the future of course I hope to become a world champion — that is also a dream."
The Dutch teen, who is in bidding to win this year's European Formula Three title, will become the youngest F1 driver when he takes his place on the grid at just 17 when the next campaign gets underway next March.
Like four-time champion Sebastian Vettel, he excelled at kart racing and was crowned world champion last year.
Racing runs in the family and his father, Jos Verstappen, is well placed to offer advice, having competed in 106 GPS from 1994-2002.
___
SLIPPERY SPA
While the Monaco Grand Prix, with its glittering harbor and gleaming yachts, is the most glitzy on the F1 circuit, the Spa GP is the longest and most demanding.
Nestling deep inside the Ardennes forest, the Spa track is 7 kilometers (4.3 miles long) and tests drivers and tires to the limit with its mixture of fast straights, dangerously fast turns and sweeping elevations followed by sharp descents.
"The height difference is so great that you always have the feeling of riding a roller coaster — especially in Eau Rouge," said four-time champion Sebastian Vettel, who won here last year.
The location of the circuit and its huge size also means that it can be dark and rainy on one part of the track and sunny somewhere else — a unique microclimate in F1.
"The weather can also be very unpredictable and a challenge for drivers and teams, it should never be underestimated," Vettel said. "The track is one of my favorites of the year because it feels like it has grown out of the nature that is all around. It blends with the natural setting perfectly."
____
SWITCHING CARS
Le Mans 24 hours champion Andre Lotterer makes his F1 debut at Spa for Caterham this weekend, replacing Japan's Kamui Kobayashi on a one-race deal.
The 32-year-old Lotterer, a three-time Le Mans winner with Audi, finally gets a chance to impress in F1 after a brief spell as a test driver for Jaguar in 2001 and 2002.
"I'm ready for this challenge and I cannot wait to jump in the car," he said. "I will need to get settled and used to the car quickly, as the team has worked on a number of updates."
The Caterham team has yet to win a point this season. Swede Marcus Ericsson finished 11th at the Monaco GP in May, the team's best result of the year.
____
SOCHI READY
The Russian GP is set to go ahead as scheduled in October after the track was passed fit after a visit by motor sport's governing body.
The Autodrom in Sochi has been built on the site of the Winter Olympic Games, held earlier this year. The race is scheduled for October 10-12.
"The circuit is in extremely good condition and will be issued with a license," said Charlie Whiting, the FIA's race director. "The kerbs are very good, the verges, the guardrails, the walls - everything is in an extremely good condition. I can say without hesitation that the circuit is ready 60 days in advance, which is very rare really."