Two races in, and patterns are already starting to emerge in Grand Prix's junior classes. In Moto2, preseason favorite Tito Rabat is living up to expectations as his challenges fall by the wayside. In Moto3, Jack Miller has a far firmer stranglehold on the class than expected, while the new Honda NSF250RW is proving that when HRC put their minds to building a factory race bike, the competition had better watch out.

Austin, Texas, proved to be a case in point. A bizarre start to the Moto2 race saw a massive pile up at the treacherous first corner, the run up the hill combining with the massive nerves of a Moto2 start – arguably motorcycle racing's most rabid class – to produce chaos. Josh Herrin, feeling the strain of coming in as reigning AMA Superbike champion to find himself running anonymously in mid-pack in Moto2, ran in to Turn 1 too hot, try to jam his Caterham Suter into a spot which wasn't there, and ended up taking down half the field. Herrin was understandably nervous in front of his home crowd, and feeling the pressure of being the ambassador for American racers, but he did himself and any AMA hopefuls looking to Moto2 a disservice. Herrin fractured a collarbone whle training, and so will have to wait until Jerez to start to make amends.

Championship leader Tito Rabat also got a mediocre start from pole, then dropped back a long way in the first couple of laps, before starting to fight his way forward again. Xavier Simeon looked like making it a very big day for Belgium for most of the race, before massively outbraking himself on the way into Turn 1 as he came under press from Dominique Aegerter and Maverick Viñales. Aegerter led for a while, but he could offer no resistance to Viñales. The reigning Moto3 champion quickly opened a gap and crossed the line with a comfortable margin to spare.

Viñales took just two races to bag his first win in the intermediate class, a deeply impressive feat. The step between the tiny, lightweight Moto3 bikes and the heavy, wide Moto2 machines is huge, much bigger than the difference between Moto2 and MotoGP, so to adapt so incredibly quickly is quite an achievement. Just to underline the fact that he is something a little bit special, Viñales became the second youngest rider to win a Moto2 race, a year and 4 days older than Marc Marquez when Marquez won his first race. But Marquez took four races to, Viñales did it in two. The young Spaniard's market value has surely increased, with speculation already starting on where he might end in MotoGP. Factories will surely have precontracts with his name on it, just waiting for the signature of the young Spaniard.

Can Viñales win it all in his first season? He sits second in the championship behind Tito Rabat, just 7 points down on the leader, so you can't rule him out. Yet if anything, Rabat showed he is ready to become a champion at Austin, by working his way calmly through the field and settling for second place. The old Tito Rabat would have panicked earlier and pushed too hard, throwing valuable points away. The massive crash Rabat had during testing at Phillip Island before the season began helped impress upon the Spaniard that championships are won by managing risks, rather than going for it at the first attempt.

In the Moto3 race, Jack Miller showed once again that he, too is a bit special. The Australian led almost the entire race, though he had company throughout. First from Efren Vazquez and Alex Marquez, later from Vazquez and Alex Rins, the Hondas getting tangled up with each other. Almost literally, in the case of Marquez, who managed to throw his Estrella Galicia Honda up the road on the penultimate lap.

The Moto3 race also showcased the differences between the KTM and the brand new Honda. Both bikes are close on horsepower, though it looks like the new Honda may have the upper hand now – a radical change from the weak and underpowered NSF250R from the past two seasons. But the KTM is stronger in braking, remaining more stable on the brakes, according to Miller. That was also the area were the 2014 Honda appeared worse than the FTR chassis Miller rode for the past two season, the NSF250RW lacking braking stability and turn in, according to Miller's view from the outside.

The difference between the Honda and the KTM was clearest of all at the end of the back straight. Vazquez, getting better drive off Turn 11, flew past Miller along the back straight lap after lap. Untroubled, and unhurried, Miller let Vazquez past, content to wait for the braking zone. Slamming on the brakes much later, Miller simply slid back up the inside of Vazquez to regain the lead. There was nothing Vazquez could do about it.

Miller looked like he had the race completely under control. After the race he confirmed that he had never been worried. 'I felt quite strong,' he said. 'I tried to keep the pressure on. If Efren came past I tried to pass him straight back, almost try to play a mental game, make him start thinking about how he's going to do it. I feel it paid off at the end.' He was benefiting from the years spent on the underpowered FTR Honda, having to exploit the strength of the chassis to compensate for the weakess of the engine. But those were skills he had learned much earlier, he said. 'You guys only remember last year, but ever since I've been racing a road bike, I've been on the slowest one on the grid, so I've learned how to be deep on the brakes, that's for sure,' he told us.

Miller held off all challenges to the end of the race, winning by a slim but insuperable margin. Romano Fenati took second, the Italian finally benefiting from a competitive bike, having previously been on an FTR Honda like Miller. Efren Vazquez finished third, for the second time in two races, and is now second in the championship standings. Alex Rins took fourth, but if Rins – or even Alex Marquez – have any pretensions of the championship, they will have to start to make progress soon. With Miller in his current form, and displaying an enormous amount of maturity, he is going to be a hard man to beat.

So what of Argentina? It is hard to say. The track is clearly fast, with a couple of spots of very hard braking, but also a few flowing points. In the Moto3 class, it will likely favor the KTMs, with the braking zones outnumbering the acceleration points, where the NSF250RW has so far been strongest. As a completely new track, it should be a level playing field for everyone in Moto3, the spoils going to the rider who can learn his way around fastest. The pressure will be on the Estrella Galicia pairing of Rins and Marquez, who need to start scoring solid points. The test for Miller will come if they manage to put any pressure on him. Winning a title means learning to accept that second or third is better than crashing out. So far, Miller has been rock solid.

The playing field is not quite so level in Moto2. Tito Rabat and Nico Terol tested there at the beginning of July last year, but as that was shortly after the track was completed, it was hard to get a real idea of just how fast the track is. The circuit was dirty and green, so all Rabat and Terol learned was which way the corners went. That may be a short term advantage for the pair, but come Sunday, it is unlikely to make much of a difference.

That still puts Rabat very much in the driving seat, however. His main challenge could once again come from Viñales, the Moto3 champ quick to learn new circuits. It will be interesting to see where Rabat's focus lies, who he concentrates on beating. Terol, Luthi, even Corsi and Cortese, these were the men hotly tipped before the season started. So far, though, Rabat's real challenge has come from Viñales, and give the prodigious talent of the HP Pons rider, he would do well to keep an eye on the Moto3 champion. The return to Argentina promises to provide some intriguing racing.