Formula 1 2012: four winning drivers, four winning constructors and nobody managing to hold the championship for more than a single Grand Prix weekend. Who's next?The F1 circus is heading back to Europe after the opening long-haul phase of the championship in Asia and the Middle East with plenty to mull over and the next race winner, let alone the title championship, is anyone's guess.McLaren team principal Martin Whitmarsh put it this way: "It's a much more interesting championship right now than I would like it to be, it really is."ROOKIES EMERGEIn March 2012, it looked like McLaren could be set for a year of Red Bull-like dominance. Lewis Hamilton started the first two races on pole with team mate Jenson Button completing the McLaren front-row sweep in Australia and Malaysia.Button won the opening race in Melbourne but rain-hit Malaysia was a race against the odds and was won - to everybody's surprise - by Ferrari's Fernando Alonso in a car that everyone thought was off the pace.Then, in China, Mercedes swept the front row, thanks to a grid penalty for Hamilton, and Nico Rosberg took the first win by a Silver Arrow since 1955. Hamilton, still without a victory (only third places), was championship leader.In Bahrain, a race held against a backdrop of nightly clashes between police and anti-government protesters with tear gas and petrol bombs, 2011 World champion Sebastian Vettel won and toppled Hamilton. For the first time since 2003, no driver had managed to take a repeat victory in the opening four races. The sport has witnessed Rosberg's first win in 111 starts, Sauber's Sergio Perez taking the first podium finish by a Mexican in 41 years and Romain Grosjean putting France back in the top three for the first time since Jean Alesi in 1998.The one constant, apart from Red Bull's Mark Webber racking up four fourths in a row, has been the influence of the Pirelli tyres on grands prix.SWEET SPOTMercedes managed to find the "sweet spot" in Shanghai but McLaren was completely unable to find it in Bahrain where its drivers punished their rear tyres.Whitmarsh said: "Clearly we did something wrong. You look at our (race) pace by comparison to the long runs on Friday and we were a second slower. A second slower is 30 or 40 points of downforce. Well, we didn't lose 30 or 40 points of downforce. These tyres are very challenging. If you get in the sweet spot then you are in great shape and if you are out of it you are in for a pretty tough time."The next race, the Spanish GP in Barcelona on May 13, could see yet another winner. Kimi Raikkonen, the 2007 champion now in a comeback season after being absent in rallying for two seasons, came close to passing Vettel for victory in Bahrain, while Hamilton had still to win.Mark Webber and Mercedes' Michael Schumacher both know they have winning cars and so too, for that matter, does Ferrari's Felipe Massa. Even Sauber could spring another surprise.China showed how little separates the leading teams but over next three weeks, with teams testing at Mugello in Italy before Barcelona, could bring another shift in in the pecking order.Whitmarsh said: "You can't rest on your laurels in F1. The four races have all been very different in complexion. Who knows what's going to happen in the next one? That lack of predictability is great for fans."