This does not work that well because : 1) Re-ranking is only good as the results you originally get. If you get garbage in, you will likely get garbage out, no

This does not work that well because : 1) Re-ranking is only good as the results you originally get. If you get garbage in, you will likely get garbage out, no matter how you re-rank 2) Re-renking using semantic search does little to help with the main problem in search (SEO spam, low quality content). These 'bad' pages typically rank well in semantic search and re-ranking would probably just help boost them.