Spiders don’t need to be crawling around anything in /wp-admin/, so that’s disallowed. Likewise, trackbacks, xmlrpc, and feeds don’t need to be crawled, so blocked those as well.
User-agent: *
Disallow: /wp-admin/
Disallow: /trackback/
Disallow: /xmlrpc.php
Disallow: /feed/
Sitemap: http://www.psba.com/sitemap.xml