A critical point of a polynomial means a point where its derivative is 0. Smale's Mean Value conjecture states that for any polynomial P that has degree at least 2, and any complex number z that is not a critical point of P, there exists some critical point c of P such that

|(P(z) - P(c))/(z-c)| ≤ |P'(z)|

Note the order of quantifiers: c can depend on z, so there does not have to be one critical point that does it for all z.