SERPs ranking when 2 keywords omit space in between

Its my first post..please welcome me :)

[logiic]

Hi All! I have recently had a strange observation which I want to discuss. Support there is a keyphrase 'A B' (with space in between), and there are 2 web sites Y and Z. A search for 'A B' (no quotes, with space in between) ranks Y on position 1st, Z on position 2nd while a search for 'AB' ranks Z 1st and Y 2nd. What complicates this behavior is web site Z has this term only once in the page, does not have it in URL either (Still it ranks 1st for 'AB' while web site Y has 'AB' in the URL and many times throughout the body. Y has 135 backlinks for this page while Z has only 15. Keyword density is more in Y. I cant understand why Z ranks for 'AB'. Does it say anything about Keywords in URL ? (I hope it all makes sense)

[Receptional Andy]

Welcome to WebmasterWorld, logiic :)

Is it right to assume you're talking about Google rankings for the keywords? If so, Google's separation of words that run together is relatively complex - or at least, I've never quite figured it out myself. There seem to be certain conditions that cause a URL to rank for joined-together words that are distinct from the rankings for the words when separated. Unfortunately, while I have a few theories, I don't know what those conditions are ;)