Re: 60 to 70% accurate?
Hyper partisans see themselves as being only slightly left or right of center - they believe they are part of the "silent majority" in the country.
A good way to approach this is to look at your opinion and try to find views that are more extreme in a variety of directions. If there aren't any, you're probably out on the fringes. If you are more lazy, you may find the first chart in this article helpful. If you are both lazy and an extremely right-leaning partisan, you will find the second chart to be more your cup of tea.