I always glance through the "Questions that may already have your answer" section on the Ask Question page before posting since it frequently contains a post that already answers my question, and is a good way to double-check that I'm not posting a duplicate.
The results used to be so relevant to my question that before you updated your search engine, I used to use the Ask Questions page a lot to search for questions because it was was better at bringing up relevant posts than the actual search page.
But lately it's been useless to me. It appears that the top results are almost always highly voted posts that contain one of the words in the title, and the algorithm is not very good at picking out which words in the title are actually important and which are not.
For example, take a look at the difference in results between the "Questions that may already have your answer" search results and some actual SO search results when looking up something like "C# Convert List to 2D Array":
This is only something I started noticing in the past few days, so I'm assuming you made a change to this recently which broke it.
I think it's too strongly weighted against how many votes a post has. For example, almost any question containing C, C++, or C# in the title brings up the C++ book question as one of the top "Questions that may contain your answer". And SO's top voted post about sorted vs unsorted array performance comes up in most of my tests, including a title of "test test test test test"
Can you fix this query so it goes back to returning relevant search results instead of mostly returning popular questions containing the same words?
site:stackoverflow.com
is 820% better (made up figure, but it's better in my experience)