World champion Sebastian Vettel is favourite to open the Formula One season with a victory at the Australian Grand Prix this weekend but there are strong indications he will face a much tougher challenge than he did last year.
The German's pole-to-flag victory in Melbourne last year started a second season of dominance for Vettel and his Red Bull team that culminated in the retention of drivers' and constructors' championships.
Despite the millions of dollars invested in building the cars and the thousands of kilometres run in testing, no one really knows how the contenders will match up until the covers come off the tyres for Saturday's qualifying session.
Vettel's team-mate Mark Webber says every team will be anxious.
The return to the grid of Kimi Raikkonen after a two-year sabbatical has resulted in the tantalising prospect of five former world champions, not to mention a string of young pretenders, fighting to deny red Bull another title.