I won't (and shouldn't) go into specifics, but people in the search engine biz do a lot of comparison and contrast between search engines. They rate their own results and their competitor's results, both in a vacuum and in groups.
Yahoo!'s search was not one of the best sets of numbers I've seen. Google consistently came out on top. Particularly for longer queries, Google is notoriously good at these by comparison to other keyword search engines.
But it might be that was for our dataset bias. You can get surprising boosts in relevance for specific datasets by biasing towards them in your index and ranking algorithms.
Yahoo!'s search was not one of the best sets of numbers I've seen. Google consistently came out on top. Particularly for longer queries, Google is notoriously good at these by comparison to other keyword search engines.
But it might be that was for our dataset bias. You can get surprising boosts in relevance for specific datasets by biasing towards them in your index and ranking algorithms.