GMAT first try...

Dear Franck,

I greatly agree with Ms. Loo,
Kaplan can go as high as 100 points below the actual score, but PP is usually within 30 points.

As to the minimum/average score for a school, you can check the school's profile on business week or else and see the average score. Probaby anywhere below 50 points of the average is going to be a bit tough, but not impossible. Thus if a school has 710, you can easily walk in with 670.

A lot of times top 10 won't care about the score but want to keep it high becuase it plays in the rankings.

moreover, if you want to claim superior analytical abilities and get only 40 on math, it will be a conflict/disparity.

By the way, are you trying european or US schools? You said 20 best... Often Europe and USA are very different in what they are looking for... for European schools GMAT is not as important, though they have to keep it for the sake of accreditation. It is totally possible to get in a good European school with less than 600. Not because the school is bad, just not much attention is paid to the GMAT. I had a few friends in Barcelona and Rotterdam with low 600's and high 500's.

--Bogdan.