Parcel Search - How accurate is appraised value?

[Andrew Bissada]

I watched Brandon's video "How I quickly analyze a rental property for cash flow"

Towards the end he mentions using the county's parcel search to get an idea on the appraisal value of a property (to see if you can realistically offer lower than asking price).

I tried this out to see how it works, on a property on zillow listed for $275,000

The appraisal value from county parcel search was $241,848.

That is a 33,000 difference. How accurate might this be? And how likely would it be that I could offer a price like that to purchase?

I don't necessarily want this exact property, but I want to be able to use this process when I find properties I do really want.