Ask them how many lines of code they've written. (Score 1)

A good way to test this at interview is to put a keyboard in front them and ask them to type as fast as possible. The smart ones will use copy-paste. The even smarter ones will use VB. Generally the more experienced ones will have written more lines of code (ideally in a very hard language such as Java, further demonstrating their sophistication) and this means they are definitely better.