Many F1 fans have many things to say about Tilke's circuits with the general consensus being that they are boring and don’t promote exciting racing. This is possibly correct with the majority of his company's designs; they have given us places like Valencia and Bahrain. So why are they boring? Generally the problem is that his circuits either don't create enough of a challenge or don't provide any easy places to overtake on. There are many roots to these elusive qualities, so what are they?

Lets start with the factors in overtaking:

• How fast the cars can travel round corners - this can bring on whether a corner is tight enough to provide a large enough breaking zone
• What's the corner beforehand - Deciding how close the cars will be
• How long is the straight directly beforehand - DRS now takes a massive part in this
• How tight is the corner - Decides whether two cars can travel side by side through the corner
• What's on the track side - Deciding whether a driver can run wide or push wide

The first one is the only variable in this situation and over the years some corners have been made redundant because they can now be taken quickly. Especially when ground-effect arrived suddenly corners became redundant and driven through as if they weren't there. For Tilke this is a problem and whilst talking to F1 Racing in their February 2012 issue he explained that it is very tough to decide whether a corner will be slow enough for the regulations. Here sympathy can be given.

Before and after

However not when you look at the second and third factor - the corner and straight before. If you look at the circuit design at all the circuits that have common overtaking zones there is a common theme amongst them. The corner before is mid to highspeed corner leading onto a longish straight. This is or was the case at Adelaide, Spa, Monza, Silverstone, Indianapolis, Montreal, Shanghai, Malaysia, Hockenheim, Nurburgring, Japan, Sao Paulo, Portugal etc. Looking at the amount of circuits that have this you'd think that overtaking was more common place however getting this sort of layout can generally only be fitted once in a circuit plan. But why does this work?

Tilke does have the long straights but very rarely has he used the fast corner before

This track layout works because of the spring effect. In slow corners cars bunch up but stretch out when leaving the corner. This doesn't provide a chance for overtaking because the driver can't gain the gap lost in time for the next corner. However in a mid-high speed corner this spring effect is not as dramatic allowing the driver behind can stay close behind onto the next straight where they will get enough of a tow to pull up alongside. Now the straight doesn't have to be particularly long because if the cars are running high enough downforce then there will be enough time to pull alongside. Tilke does have the long straights but very rarely has he used the fast corner before. When he has it has led to some fantastic overtakes in Turkey, Malaysia and China. India was the biggest disappointment as many expected there to be overtaking but this isn't the case as the corners before its long straights are both hairpins, which suffer from the spring effect most.

The tightness of the corner is paramount. At Silverstone Brooklands is a bad example of an overtaking corner. It is too open and too fast for a car to gain an advantage through braking but it does provide a chance of cars travelling side by side. Generally a good overtaking corner has a large braking zone like in Monza and Spa. Hairpins are especially good for this as they have a large braking zone. However, they have another trick up their sleeve – they allow for a cutback if the overtaker runs wide. Tilke understands this and most of his overtaking corners are hairpins or tight corners.

But cutbacks are not possible when there is a wall on the outside of a corner. This is why street tracks are hard to overtake on. Generally a circuit isn’t wide enough for two cars to travel through a corner. This means having space to run wide or cut tight means that a driver is more likely to battle for position. Not only this but if a driver can see the exit they can decide where they will have to position the car on the exit but at places like Valencia, Singapore etc. a driver has to guess at how much space they will have left for the opposition on the exit.

Aiming for perfection

So through a combination of track width and surroundings, straight length, prior corners and driver confidence the perfect overtaking corner can be achieved. Simple you may think. However, you’ll be wrong; the car set up, the tyre type and many other factors affect overtaking. However it can be seen why Valencia in particular is not very good for overtaking. Before any overtaking corner the straight isn’t long enough and because they aren’t strictly straight meaning a driver can’t pull up alongside, walls line the side and the exit of the corners are generally tight and not wide preventing cars from driving side by side at any point.

So what makes a track exciting? Well again with the change in cars difficult corners vary even on tracks like Silverstone and Spa. India’s circuit is a very exciting circuit with fast corners and corners that challenge the drivers. Here India follows Tilke’s other successes like Turkey. There is a common feature on all exciting tracks and that is undulation. Undulations in the circuit add character and change how a corner is tackled. Spa, Nurburgring, Turkey, Sao Paulo, Brands Hatch are prime examples of this. Here Tilke has a problem as quite often he gets given a very flat piece of land to work with and unless (like in India) they have a large budget to shift lots of land this won’t happen.

So really there are so many factors that impact a circuit Tilke gets it more right than many others. Historic tracks became good through years of testing and evolving. They’ve been ‘naturally selected’ and no matter how hard anyone tries it’s very hard to create an exciting Grand Prix circuit. Personally I think Tilke comes short with overtaking but with circuit design and infrastructure he is the best in the business and so in conclusion he is unfairly criticised for what his company churns out, even if Valencia is one of the single most boring circuits ever to host an F1 race.