password rules

[casualjim]

The password rules forces hard to remember passwords. I was wondering if it would be possible to have a complexity score instead of requiring different character types.

A 21 char all lower case string is a stronger password than a 6 char string with 4 different character classes.

For example:
AB.word5 takes a dumb program about 60 minutes to crack

life is great on earth takes that same dumb program centuries to crack