NOTE: In the beginning we were redirecting https://domain.com/stats.php?player=name to https://domain.com/p/name (so some of the answers may pertain to that), but now I am redirecting to https://domain.com/@name
There is still one unresolved issue though. I wish to make https://domain.com/stats.php?player=name automatically redirect to https://domain.com/@name when visited.
<IfModule mod_rewrite.c>
ErrorDocument 404 /404.php
RewriteRule ^@(\w+)$ stats.php?player=$1
Options +FollowSymlinks
Options -MultiViews
RewriteEngine on
RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule ^([^\.]+)$ $1.php [NC,L]
</ifModule>