trilogy6202 To be fair it is indeed only based on "entropy" but I think you're misunderstanding the term or thinking it's only about password length.
Example:
Choosing a logical pattern to create a 5 digit password from a character set of 30 will always have a lower entropy than a randomly chosen 5 digit password from the same character set.
Why?
Because password entropy is determined by the number of possibilities a password can be created from a specified character set.
Now by applying a logical pattern you're reducing the number of possible passwords created (and therefore the entropy) using a specified character set since not all 5 digit passwords follow your logic and have to be discarded from the possible pool of passwords.
Practical example:
Password conditions (my created logic):
5 digits
ends with even number
starts with a letter
lowercase Latin alphabet
This gives us 363 * 26 * 5 possible passwords.
Possibilities for passwords chosen at random are:
365 (which is a larger number).
As you can see choosing a random password from the same character gives you always a higher entropy.
Password entropy doesn't mean password length!
The following passwords chosen randomly: "password" and "bgpxoqky" have the same entropy if chosen from the same set of possible passwords.