Hard tyres shed less marbles but cars go around corners faster with softer, "stickier" tyre compounds. Hard tyres last longer than soft tyres. This is why tyre strategy is such an important part of Formula One. Tyres do not wear at a constant rate: wear depends on many factors

- how smooth or rough the racing circuit is (think how it hurts when you rub your hand hard across a piece of sandpaper) and when a car is sliding on an abrasive surface on a dry corner, the grip is at its highest - and so is the tyre wear

- whether the track is dry or damp: damp means more sliding but less friction so the tyres last longer

- how hot the track is - tyres have an operating window - that's a temperature range where they are the most effective. However, that operating window relates mainly to internal temperature within the tyre. Track temperature is a different issue: hot tarmac is sticky, very hot tarmac is less sticky, cold tarmac also less sticky. These all affect adhesion and adhesion affects wear and wear creates marbles. Wear there are other factors about wear but it's the marbles that make racing less good than it should be.

So let's look at exactly why that is.

When one car needs to overtake another, it has to find a way around. If the racing line is only one car wide (as it is after a handful of laps in Singapore, for example) the overtaking car must go onto the marbles which then stick to the hot tyres. Worse, they may stick only to part of a tyre, or to only one or two tyres. Formula One cars are precision instruments and even one tyre that's not exactly as it should be will destabilise the car.

When the car is on the marbles, they live up to their name and they move around under the car. When the marbles are stuck to the tyres, they move around and cause vibration. Both of these things reduce the optimum performance of the car which has just made an overtaking manoeuvre.

The situation is worse when a car is being lapped: the car that is being lapped is required to move over. That means that car suffers the penalties that arise from going onto the marbles.

It follows, then, that there are three aspects of racing that can be modified to improve the spectacle: the rules under which racing is run, aerodynamics and tyres. Over the years, all of these have been modified. If enough notice is given, say for new rules to start in 2020, could racing be made more even without throwing away all the existing knowledge and investment but in such a way that would contain the in-season costs? And while we are at it, are there ways that the championship might be improved, too?