Flash is a propriety plug-in created by Macromedia to infuse (albeit) fantastically rich media for your websites. The W3C advises you avoid the use of such proprietary technology to construct an entire site. Instead, build your site with CSS and HTML ensuring everyone, including search engine robots, can sample your website content. Then, if required, you can embed media files such as Flash in the HTML of your website.
I used to think it could take more to get a subfolder trusted than say an individual file and I guess this sways me to use files on most websites I created (back in the day). Once subfolders are trusted, it’s 6 or half a dozen, what the actual difference is in terms of ranking in Google – usually, rankings in Google are more determined by how RELEVANT or REPUTABLE a page is to a query.