The date of the USA GP is well known in advance. The layout of the track is wellknown, all forces that will affect the cars and the tyres can be totally computer simulated these days. So what is required of the tyre manufacturers? That they come up with a tyre that meets the requirements of this particular track. That means a compromise between the level of grip required on the very slow infield part of the track and the strength of the left rear tyre to survive the forces in turn 13. The car manufacturer will set up his car with a similar compromise, and will start working from there.
Now if one tyre supplier can not guarantee that his tyre is strong enough to stand the expected forces it is a bit of a mockery to request for track changes. That would throw all the work done by the other tyre supplier into the bin. So the statement of the Michelin teams that FIA refused to change the track layout is pathetic, because this is supposed to be a level playing field, and if one group gets it right and the other does not, then it is the latter's problem and the first group should not suffer from it.
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