That is only useful if you also specify yhe conditions under which the "cracking" takes place. Do you mean on-line password guessing? Or do you mean brute-forcing a hashed password leaked from a database?
In case 1 a lock-out policy would quite easily negate your attack. In case two the hashing algorithm used is often more important than the length and complexity of the password (up to a point of course, but that point is nowadays well beyond what's pactical for a user)