We are now just days away from the opening Grand Prix of the season and if Toto Wolff's comments are to be taken at face value the dominance of Mercedes could be a thing of the past. Of course it could all be mind games from the German team's head of motorsport, but he has portrayed himself as genuinely concerned that rivals have caught up over the winter.

Mercedes won by 296 points in 2014, 275 points in 2015 and 297 points last year, making it the most dominant team in the modern era. Its drivers have finished first and second for the last three years running. But Wolff has sent alarm bells ringing with his recent comments, that come in the wake of rule changes designed to make the cars faster, wider and more aesthetically pleasing. Red Bull was expected to be Mercedes' closest competitor this season, but in testing in Barcelona it was another team that emerged as the leader, Ferrari. The Italian team lapped around 0.7 seconds faster than Mercedes. Wolff now thinks they may have the edge at the first Grand Prix of the season, which takes place in Melbourne, Australia.

"What we've seen from Barcelona is that the margins at the front of the field have shrunk," he said. "We'll see how that pans out in Melbourne, because we still don't know about the fuel loads, weights or power settings of the other cars. We take every one of our rivals seriously and respect every team's ability to find that magic bullet. They are all full of very clever people, the best in the world in their fields.

"We have done the best job we possibly could over the winter and, if we are not the fastest in Melbourne, then it's about finding out why and what needs to be done to get us back to that top spot. It's a challenge we will take on with great motivation and energy. Setbacks can provide a long-term opportunity because you constantly need to improve yourself."

The bookmakers are now anticipating a much closer battle than they did when they first set the lines a few months ago. Mercedes' Lewis Hamilton is still favourite to win the Drivers' Championship, but he is not odds-on, and new teammate Valtteri Bottas does not hold the position of second favourite. That honour goes to Ferrari's Sebastien Vettel, a four-time champion during his time at Red Bull, which dominated before Mercedes stepped it up a notch.

Many fans and neutrals are hoping for the end of the one-team dominance pattern, and will be desperate to see Red Bull and Ferrari give Mercedes a real headache this season. Based on SBR betting sites rating, it looks like we could be in for a thrilling season as these top online bookmakers anticipate a close fought battle in Melbourne. Hamilton is 5/4 favourite, followed by Vettel at 7/2, Bottas at 6/1, Vettel's teammate Kimi Raikkonen at 8/1 and then the Red Bulls of Daniel Ricciardo and Max Verstappen, who are both 10/1.

Despite all the noise, all the bluster and all the apparent worry from Wolff, right now it seems folly to bet against Mercedes. The team has been the best in the business for three years in a row. Of course the other teams will have improved over the winter, but so will Mercedes - and that could be a terrifying prospect for rivals. It is not for nothing that Mercedes is 1/2 favourite to claim a fourth consecutive title. In the first race of the season Hamilton will be desperate to assert an edge over Bottas and land a psychological blow on the rival teams, so backing him at 5/4 looks a good option right now.