So I've been using SERPbook to track my positions for a new site. When I logged in to SERPBook, I received an alert notification that my site's ranking has dropped from 1st to 200+. I thought it was a temporary google dance or something. To double confirm, I even used their integrated live query to see my rankings and it really isn't in the first position anymore. However, when I use Google's Chrome incognito mode to check my ranking, it was still first. I logged in to my VPS and check too.. and yeap, it was still in the first position. And yes, all of them without logging in to Google account. Browser's cached all cleared. So how accurate is those SERP checkers really?