More executable paths through code correlates with higher likelihood of bugs

The McCabe Cyclomatic Complexity metric (which counts the number of different executable paths through a module) proves to be an excellent measure of code quality. The more paths through a program, the more complicated it is, and the more bugs the program is likely to have.

http://www.enerjy.com/blog/?p=198

if we know nothing else about a file except that it has a high Cyclomatic Complexity value, we can now have more reason to believe that it is likely to cause problems (keeping in mind of course that there are no guarantees about anything in this life).