I find that Google's SERP is quite to the expected but Yahoo seems to be primitive. Why there is so much algorithm difference between the two in this competitive word?
yahoo consider meta tags yahoo looking more on page optimization, google on backlinks google place trusted (.edu for example) higher
Google and Yahoo have different algorithms. Yahoo is still one of the meta based pattern search engine. It concentrates on text and meta details. Google is advanced crawler based search engine. This makes the major difference in their SERP.
Yahoo and google are different search engines. Yahoo focuses on text and meta details while Google focuses on relevant links.