There are bunch of info you can get on how to optimize website for Y..
here are some tips that Y wants included in it's Index..
-original and unique content
-webpages should be designed for humans,secondarily for SE's
-Metadata that described accurately the content and of the web page
-Good web design
-Related content and links that intend to help people's interest..
-pays attention to number of backlinks
-gives some weight on domain age
-more relevant sub pages
-linking to authority sites