Round three of my midseason analysis and we are faced with three intriguing cases. Each of these teams has had good days but they have also been tempered with catastrophic lows. Incredibly enough, the comfortable championship leader drives for one of the three teams which is perhaps testament to how well he is driving this season. Today I'll be looking at the seesaw performance of Sauber, Mercedes and Ferrari. The fact that these three are mentioned together in this section shows just how unusual this season has been.

Sauber

Sauber have been the most consistent of the three and are having a great season, particularly when you consider the size of the Swiss outfit. Two podium finishes for Sergio Pérez are results that Sauber dream of and they have performed well with nine points finishes between the two drivers. Sergio Pérez has led the team well and has really matured, ready for his likely move to Ferrari next year. He has 14 more points than Kamui Kobayashi, mostly down to his podiums. They have already got as good as double the amount of points from the whole of the 2011 season, where they ended seventh with 44 points.

There are three key factors in the transformation. Firstly, as already mentioned, Pérez is a lot more mature and taking advantage of just about every opportunity; he has 47 points already when last season he managed only 14. Secondly, being a very small team on a small and sustainable budget, they have benefitted by far the most from the loss of blown diffusers because it was a technology that they simply couldn’t afford to invest in.

And finally, Sauber can work miracles on their tyres. The car is so soft on the rubber that it allows Sauber to be conservative on strategy and still perform well on Sunday. The car is so good at tyre management in fact that it is becoming an Achilles heel on Saturday as they can’t heat the tyres up for one lap, particularly in cold or wet conditions, which leaves Kobayashi and Pérez lower on the grid than they deserve.

Big Result: Either of Sergio Pérez’s drive could go in here but they were both drives that were aided by unusual races. As a result, I think I have to credit Kobayashi’s drive to fourth in Germany as the best drive. He kept his nose clean, got the strategy to work and benefitted from a little fortune, including Vettel’s post race penalty.

Missed opportunities : In amongst Sauber’s glittering season, there is a glaring result that they will rue for years. Sergio Pérez’s brilliant drive in Malaysia left him second, catching Alonso by seconds per lap. He caught up to him, and then pitted too late and then caught him again and ran wide of turn 13, ruining his chances of a maiden win. Despite their best ever non-BMW result, the atmosphere reeked of ambivalence post race.

Top dog: Kamui Kobayashi has been rather shown up by the sophomore Pérez. Kamui hasn’t had a bad season but in amongst a run of two points in four races, there were definite rumblings about his 2013 seat, purely because of the level Pérez has been performing at. Kobayashi still edges qualifying but he’ll have to start clawing back the 14 point deficit if he is to progress into higher F1 circles.

• Sergio Pérez A
• Kamui Kobayashi B

Mercedes

The Brackley based team are heading backwards faster than Pastor Maldonado’s Williams in Venezuela. The season started with such promise too. They were the team to beat in qualifying with their double DRS, even if it took them three races to show it, but since China they have struggled for points.

In fairness, their 106 points are less than the car deserves on true pace, thanks in large part to the technical elements of Michael Schumacher’s car; however, their performance in Hungary was simply shocking. Take Schumacher’s antics out and the weekend was abysmal. They struggled to get out of Q1 and were nowhere in the race, Rosberg rescuing a point in the end. They have only scored more than 10 points in two races since Bahrain and for a team that planned on winning the championship in Schuey’s second final year, that’s nowhere near good enough.

Big result: Everything came together in a perfect storm for Mercedes in China. The conditions suited them, they managed to lockout the front row and were able to pull away at the front as a massive train of cars held each other up. They had a bit of luck too as the biggest challengers, McLaren, suffered a gearbox penalty with Lewis Hamilton and Jenson Button was delayed by a slow pit stop in his crucial final stop putting him back in the pack.

Missed opportunities: Mercedes were plagued by qualifying errors in the early rounds. They could have been on the front row in Australia or Malaysia but for mistakes. However, they will likely rue Schumacher's post race penalty in Spain as it took away his pole position in Monaco - a race he may well have gone on to win instead of leaving Rosberg alone at the front.

Top dog: Rosberg has a clear advantage in the championship ahead by 48 points, though this is more down to Schumacher’s rotten luck than anything else. This could well be a sign of things to come as Rosberg may well end up leading the team in 2013 next year alongside the likes of Paul di Resta. That though, is entirely dependent on Schumacher’s decision.

• Nico Rosberg B
• Michael Schumacher B-

Ferrari

The Scuderia started the season with an absolute dog of a car. They expected to be in the midfield early in the year, and that is exactly where they were, although they were aided by a downpour in Malaysia.

All of the eggs are in the Spaniard’s basket, which could prove crucial in the title race

Judging the pace of the Ferrari this year has been difficult due to the huge gap in performance between Fernando Alonso and Felipe Massa. Massa’s pace has looked up in recent races even if his results haven't showed this, but it is still unlikely to get him a drive for 2013. As it has always been since Alonso joined, all of the eggs are in the Spaniard’s basket, which could prove crucial in the title race as every other competitor splits resources between their two drivers.

Big result: Barcelona was the first time that Ferrari showed race winning pace. Even though they were unable to beat Pastor Maldonado in his Williams and were outdone on strategy by the Grove team, it was a sign of things to come as they had finished no higher than fifth in dry conditions prior to this.

Missed opportunities: Fernando Alonso has always been brilliant at damage limitation. He has done this for the majority of the season and showed this again in Hungary, with fifth place. However Ferrari may end up ruing Alonso’s result in Britain. Although second place is a good result, losing the race win in the last five laps to Mark Webber could be seven points that they can't afford to drop. Also, the fact that a second place is seen as a missed opportunity is a sign of how well Alonso is driving this year.

Top dog: Is there any doubt who the top dog is in Ferrari? While it may be partly down to the structure of the team, Fernando Alonso has been at his imperious best while Felipe Massa appears to be waiting for his contract to run out.

• Fernando Alonso A+
• Felipe Massa C

So there is the constructors’ championship positions from six to four. These three teams are having very different seasons and could be anywhere by the end of the season. It’s quite incredible to think that one of the teams yet to be reviewed has yet to win a race but is still in the championship hunt. Next week I’ll look at the final three fighting at the sharp end and look ahead to the final European races of the season (yes it’s that late in the season).