I noticed there was a jump in pageviews in Google Analytics after I resumed my posting. The increased number of pageviews were from me, they were generated by post preview. It seems that I had those in the past, I wasn't aware of those.

Because I don't have huge amount of pageviews, so my own pageviews sort of affects the accuracy of statistics in a way. I wanted to exclude those pageviews, at least for a while.

The preview URI looks like:
Side note: the host used to be on my custom domain blog.yjl.im, now it's on blogspot.com with strange hash and blog ID.

By using filter, we can exclude those from profile.

I use relatively strict pattern, only exclude post previews. There might be some other Blogger functions under /b/.*, you can exclude more if you want.

I think those preview is valid data, I may remove the filter some time in the future. If you are a statistics freak, you may want to see how many previews per post. Although, I don't know if that number really means anything useful.

You can check with Real-Time report, but note that filter takes time to be effective:

Keep in mind that changes made to profiles may take up to a couple of hours to update in Real-Time reports. We're working on reducing this latency.

Be patience. Wait for a couple of hours after you save new filter, then click on Preview button to see if post preview shows up in report.