Lewis Hamilton finds edge over team-mate Nico Rosberg in China

Four races into this Formula 1 season, and Lewis Hamilton is effectively unbeaten. He might still narrowly trail Mercedes team-mate Nico Rosberg in the championship, but it is already looking as if only bad luck can stop him winning it.

Another imperious victory in China on Sunday only heightened the impression that, in the end, Hamilton will have just that bit too much for Rosberg, worthy challenger though the German is.

Rosberg hangs on to a slender four-point lead in the championship, by virtue of his victory in the season-opening race in Australia, from which Hamilton retired, a fate that has yet to befall Rosberg so far this season.

But a third superlative drive in succession from Hamilton cannot have failed to make an impression on Rosberg. "I'm sure it's a little bit of a statement," Hamilton said.

This win was very different from the one in Bahrain two weeks ago, or in Malaysia the week before that.

In Bahrain, Hamilton was slower than Rosberg, but held him off throughout the race with one of the greatest displays of defensive race-craft you are ever likely to see.

In Malaysia, Rosberg was behind Hamilton all the way but was simply blown away on pure speed.

In China, the respective pace of the two men on race day was never on show, for Rosberg lined up fourth, made a bad start as a result of a telemetry failure - which meant the team could not set the clutch as they normally would - and then had to fight up from sixth place.

By the time he was finally past Ferrari's Fernando Alonso and into second place with 14 laps to go, the race was long over. Hamilton was in total control from the start.

Afterwards, Rosberg looked at the positives, as any driver would, but there was scant evidence that he would have been able to challenge Hamilton even if he had not had such a bad start.

It was an academic question, anyway. From fourth on the grid, with his team-mate on pole, it was always going to be difficult for Rosberg.

That was the result of another quite stunning qualifying performance from Hamilton. Rosberg was more than a second adrift, and behind both Red Bulls, their downforce and cornering ability making them a threat to Mercedes in the wet as they were in qualifying in both Australia and Malaysia.

There were mitigating circumstances for Rosberg to a degree in qualifying. He blamed a mystery brake problem for overshooting a corner on one lap, and an incorrect dashboard read-out, that said he was down rather than up on his best time so far, led him to push too hard in the final corner on the next lap and spin.

But the reality was that Hamilton was, as Mercedes co-team boss Toto Wolff said, "in a league of his own" in qualifying, and his breathtaking ability to produce that 'special' one-off lap on Saturday afternoons will continue to be one of the Englishman's greatest strengths.

After four races, then, with a dominant car, the score in terms of poles and wins at Mercedes is three-one in Hamilton's favour. And even with his Australia win, Rosberg cannot say he 'beat' his team-mate, whose engine had trouble from the start.

"In this racing business it's all psychological," Hamilton said. "It's all about positive energy, a psychological battle you're having with yourself and the people you're competing with.

"Nico's very, very fast but I'm grateful I've been able to put some really good performances in but I owe it to the team. It's incredible what they've done."

Behind the Mercedes, there are some equally intriguing patterns starting to form at the other leading teams.

The fight between Alonso and Kimi Raikkonen at Ferrari was one of the most eagerly anticipated battles of this season. Two of the greatest drivers of the last decade going toe-to-toe promised to be thrilling to watch.

The battle between two of the finest Formula 1 drivers has yet to really commence

Alonso, though, has totally dominated the Finn so far - as more than one person who has worked with both suspected he would - and the Spaniard was at his very best in China, putting his car on the podium and beating both Red Bull drivers.

Afterwards, Alonso said he had had a "fantastic" weekend on a personal level, likening his driving to his performances in 2012, when he produced one of the greatest all-time seasons to take the title fight against Sebastian Vettel's vastly superior Red Bull to the final race, and only just missed out.

Alonso must know that playing psychological warfare with Raikkonen is like trying to spook a statue. But he couldn't resist pointing out afterwards just how big the gap was in the race, even if he did dress it up as an example of how far behind Mercedes Ferrari still are.

Raikkonen had a difficult weekend in China, losing first practice to technical problems and on the back foot from then on, and has struggled with the car from the start of the season.

But Alonso is driving the same car, and Raikkonen knows now - if he did not before - that he is facing a challenge from a team-mate on a completely different level from anything he has experienced before.

At Red Bull, the dynamic is every bit as fascinating, as the increasingly impressive Daniel Ricciardo shows a clean pair of heels to his four-time world champion team-mate.

Vettel is making no attempt to hide it, saying he is being beaten "fair and square", and team boss Christian Horner admitted on Sunday that the German was "struggling, and it's difficult to explain why at the moment".

What to make of this?

There is no arguing with the scale of Vettel's statistical achievements in the last four seasons. But there was always a question about how much was driver and how much was car.

So are we now to think that what we watched was a very good, intelligent and consistent driver exploiting by far the fastest car, against a team-mate who was not able to adapt his driving style as effectively to its most powerful feature - exhaust-boosted rear downforce?

Or is Vettel truly the all-time great many believe him to be, and Ricciardo is potentially even better?

The mind goes back to a barbed remark Alonso made in a BBC interview towards the end of last season, when he was asked whether he considered the man who had stopped him winning the title three times in four years an all-time great.

Ricciardo has pushed Vettel much closer than expected

"Time will tell us," Alonso said. "There are many years [to go in his career].

"He is 26 years old, so when he will have a car like the others, if he wins, he will have a great recognition and be one of the legends in F1.

"When one day he has a car like the others and he is fourth, fifth, seventh, these four titles will be bad news for him because people will take these four titles even in a worse manner than they are doing now.

"So there are interesting times for Sebastian coming."

Those remarks will be on many minds as this already fascinating season unwinds.