... i want to know does this count only apply to post deleted by mods only ?
assuming you're talking about count on bpip.org then yes it counts only those were deleted by mods
bpip scraped data from bitcointalk modlog, and only post deleted by mods are recorded there
If we delete the post ourself or it is deleted by Self-moderated OP or the whole thread is trashed by the mods, then in these cases how do we look at them when considering good or bad posting ?
deleted post doesn't always mean bad posting
if someone deletes his own post, he may have changed his opinion and removes his comment
if a self-mod OP deletes your post, it could be simply he disagrees with you or doesn't like your post
and if you have a post in a thrashed thread, it won't add a count to your deleted post