There was a time when winning the first race of a Formula One season was pivotal. Between 1990 and 2009, the driver who won the opening round of the campaign went on to be champion 17 times. But it has been rather a different state of affairs in recent years. Between 2010 and 2018, only three times has the man leading the championship after the first round gone on to clinch the title. That probably explains why world champion Lewis Hamilton did not seem too disconcerted despite settling for second, behind Mercedes-GP teammate Valtteri Bottas, in the season opener in Australia earlier this month. There are still 20 races to go, so there is a lot of laps still to be covered between now and the Etihad Airways Abu Dhabi Grand Prix on December 1. However, Hamilton will not want to make losing to Bottas a regular occurrence and will want to hit back at Sunday's Bahrain Grand Prix. The Finn's confidence will have grown immensely from his dominant display in Melbourne, and Hamilton will be aware that allowing him to build momentum could potentially be dangerous to his hopes of a sixth drivers' title and a fifth in six years. Hamilton does have the mitigating circumstance that his car had damage to its floor in Australia, which could explain some of the performance gap between the two Mercedes cars that led to Bottas winning by 20 seconds. Bottas had been very close to Hamilton's pace all weekend, and had got the lead at the start thanks to the better getaway, which ultimately decided the race outcome. Interestingly, Bahrain is a race Bottas has been strong at in the past and it may be a tough task for Hamilton to even things up on Sunday in Sakhir. Bottas took pole in 2017 and it took team orders from Mercedes to get Hamilton past him in a race where both were beaten by the Ferrari of Sebastian Vettel. Then 12 months again it was Bottas who led the Mercedes challenge again as Vettel prevailed. Hamilton had suffered from a grid penalty that put him down the order, but he had still been out-qualified by his teammate. Hamilton has only won twice in 11 previous visits, with the most recent success coming in 2015. It is not that he struggles in Bahrain. He has had five other podium finishes there, but the past two years have definitely seen him out-performed by Bottas. Another Bottas victory would certainly make things interesting. It would underline that he has raised his game after a winless 2018, and would determine to Hamilton that he is a championship contender. Hamilton has enjoyed having Bottas as a teammate. A cynic would say that is because he has consistently proven to be quicker when it matters. How that relationship may change, if indeed Bottas has evolved into a challenger, and it will be a fascinating development if the Finn continues to get the better of Hamilton. Nico Rosberg, Jenson Button and Fernando Alonso can all attest to the fact that Hamilton does not always play well with other teammates if he gets beaten by them. Melbourne was one race but Bottas talked a good game beforehand about learning from past disappointments before backing it up on the track. If the domination that Mercedes had in Australia replicates itself in Bahrain and at the forthcoming races then it could end up being another two-horse race between the drivers of the German marque's cars. Ferrari, Red Bull Racing, and much of the F1 fandom across the world will hope that is not the case, but if it is then Bottas's ability to compete with Hamilton consistently will be crucial to an engaging season. Bottas has never finished ahead of Hamilton in successive races when the championship has still been active. Previously it felt as though Hamilton needed to have a problem, or have the title already sewn up, for Bottas to win. Australia bucked that trend. It is now a case of seeing if it was an one-off, or the start of a real inter-team duel.