Turns out, according to a French Researcher, that Google and Yahoo offer the same link in the first search result 27% of the time, according to a French researcher.

The study was done using French Search Engines though … so I'm not sure if the same results carry over here:

 "..The detailed examination of links returned is equally instructive. The first link offered by Google and Yahoo is identical in 27% of cases. In a previous study (using a slightly different protocol), conducted in December 2005, the proportion was 24%. The order of magnitude is thus similar.

The most surprising result came from the use of Wikipedia. This use was marginal in December 2005 (see study). At the time, for all 10 results on the first page, 2% of the links proposed by Google and 4% of those proposed by Yahoo came from Wikipedia. On the first link alone, Google offered no Wikipedia results (at least not in our sample) and Yahoo offered 7%.

The strategies have changed completely. Today 27% of Google’s results on the first link alone come from Wikipedia, as do 31 % of Yahoo’s."

Kinda wonder if the answer to being #1 is write a lot of WikiPedia entries and then let WikiPedia be number #1 - that's got to be easier then trying to be number one in Google and Yahoo - how many people can get up to the top 27% of the time.   But Wikipedia can, apparently.

 "..How can this sudden interest in Wikipedia by both engines be explained? It is undoubtedly connected with the increasing difficultly engines have in calculating satisfactory ranking. The good old days of PageRank algorithms are over. It was quite well suited to a fairly stable network over time that was quite highly interconnected. The explosion of blogs and news sites has changed the situation considerably. The majority of the Web is now of a volatile and ephemeral nature. In all but exceptional cases, posts and news bulletins are hardly interlinked."

Tell me about it!  Between all the stuff human evaluators do to muck up PageRank and the inability of Google and Yahoo's search algorithms to handle the varieties of content out there, created by people, properly - rankings are…well, not only hard to predict, but often don't really reflect the best content.  

Often, it's people gaming the system that makes it to the top - the Search Engines tend to act inconsistently - sometimes penalizing and other times … not (esp if the listing is from a big advertiser…it used to be mostly Yahoo that let search spam slide, but now Google is  behaving more and more like Yahoo).