"Today’s hackers aren’t typically manually going to a Website or a service and typing in passwords like "123456" in order to gain access;
that’s just not how attacks work. The modern hacker (and pen tester on the security research side) uses automated tools that typically include dictionary-type password-cracking tools. These are tools that will hit a given Website log-in form with every word combination in a
dictionary (for example, every word in the English language). So whether you choose "123456" or the word "dog," it’s just as easy to crack. -"
Via Blake Carver