Limit Liveblog Posts to 1

I saw this question asked earlier but thought I would pose it again as that thread is closed.

Is there anyway to limit the # of Liveblog posts on a page. I want only one entry at a time to be shown live. It seems doable but initial efforts at ‘posts_per_page=1’ have been unsuccessful.

Thanks for this, great simple plugin.

https://www.ads-software.com/plugins/liveblog/