RewriteEngine On
RewriteRule ^(register_player/success)(.*)$ p_register_success.php [L]
RewriteRule ^(register_player/validate)(.*)$ p_register_validate.php [L]
RewriteRule ^(register_player)(.*)$ p_register.php [L]

RewriteRule ^(player/add_comment/([0-9]+))(.*)$ p_comment_add.php?pid=$2 [L]
RewriteRule ^(player/save_comment/([0-9]+))(.*)$ p_comment_save.php?pid=$2 [L]
RewriteRule ^(player/(show)_comment/([0-9]+))(.*)$ p_player.php?show=$2&pid=$3 [L]

...