Strange results from PH searches !!!??

[Bensonv8]

Can anyone advise me on how the Piston Heads searches work.
I have used it before and usually get some strange results.
and i have again, for instance................

I searched for........
find any of the words - 'chim'
in - 'spotted TVR's
for the - 'last 6 months'
This returned 30 hits

Then i did the same search but added 'chimaera'

find any of the words - 'chim' 'chimaera'
in - 'spotted TVR's
for the - 'last 6 months'
This returned 13 hits

i wasn't sure if it would find 'chim' in 'chimaera' so i checked several of the hits and it does.
So why are there less than half the results for the second search ?

thanks

[anonymous-user]

This is the kind of question best asked before dinner and the associated consumption of red wine.

[Bensonv8]

not if you really want to understand something and remember it the next day