Changes to post affect ranking?

My WP site is 2 months old and was no4 on google.I messed up one of my earlier post and remove some pages and now Im on page 3.Is it just google dancing?I understand that google like updated content but is changing old content the same as adding more new content?

Thanks

yes, it could happen. basically, if you have more content, you need more backlink too.. sometimes, better if you have less content but got a lot linkback for each or them .. (google will think that you have a 'gold' content).