I am confused to how the searching algorithm works.

For example if I search for “Old time radio green hornet" I get about 10 hits. If I search for "Green hornet” and count the results with "old time radio" I only get about 4 hits. Same if I search for "old time radio and count the results for "Green hornet".

This seems to be the case in other search combination also.

Why does the more specific search find more results and why does the more general search miss results.

Thanks, Victor