After the first half of the 2010 Porsche Carrera Cup GB season, Ollie Jackson is leading the pro-am1 category as the stage is set for a fierce contest over the second half of the season.Jackson (Motorbase Performance) ended the first half of the season with a seven-point lead over Jonas Gelzinis (Juta Racing), with Tony Gilham (Collins ReDesign Racing) third, 22 points down on Gelzinis. Fourth and fifth are Red Line Racing's Ahmad Al Harthy and Archie Hamilton."It’s going to be a tough second half to the season," said Jackson. "Pro-am1 is pretty close. Hopefully I can maintain a gap, but one non-finish could make all the difference." Jackson is well aware that Lithuanian racer Gelzinis is proving to be a fierce contender, despite having to learn every circuit during Friday's two test sessions. "Jonas is doing well and he's pretty impressive in the way he picks up each circuit. I don't think it will take him long to learn Snetterton and I think he'll be right on me."Over the second half of the season, Gelzinis – with four pro-am1 wins to the five of Jackson – at least has the benefit of racing at two circuits he already knows. He ran at Silverstone during the pre-season test day and at the final races of the season on the Brands Hatch Indy circuit his experience from racing on the Grand Prix circuit in May will be relevant.Meanwhile, Gilham is still chasing hard despite severe budget constraints and he started the season with a pro-am1 victory at Thruxton. Also vying for their first pro-am1 victory will be Al Harthy and Hamilton, who have both shown impressive pace in their first season in the Carrera Cup GB.Jackson knows that consistently strong scores are vital to the title contest. "We do get to drop the score from one race, but I've had a couple of races where I've not finished particularly well, so I've got to be strong every time. The extra points for pro-am1 pole and fastest lap could be pivotal as well."Equally, the results of the leading pro-am1 racers against those in the pro category could be significant. "Getting a pro or two between us is really important so we've got to race with the pros," said Jackson. "That's what gave me a good lead early on; I was three or four places ahead of the other pro-am1 drivers. But you are racing against guys who are very competitive and fighting for their own positions so it increases the risk of having a problem."The Carrera Cup GB season resumes with rounds 11 and 12 at Snetterton over the weekend of 7/8 August.