I think it would be nice if the search results were "distributed" rather than deterministic.
So when i enter the same keywords, let's say there are 50 pages each of which would be equivalently good result for the search, rather than one page "winning", the search engine would alternate the winner among the many possibilities
So when i enter the same keywords, let's say there are 50 pages each of which would be equivalently good result for the search, rather than one page "winning", the search engine would alternate the winner among the many possibilities