Google sometimes redirects to results

Why does G sometimes doesn't show the real url?

[Yidaki]

As far as i remember it's been mentioned allready somewhere at WebmasterWorld but i neither remember the thread nor the answer ...

Google sometimes, very rarely, returns the resultpages with every url encoded as a redirect url instead of the real urls.

Example:
[google.com...]

After reloading the same search returned the common type result page.

Does someone know why? Does google count the clicks randomly or for every N search?

[Brett_Tabke]

They are just studying click through rates on selected keywords. They've done it since almost the beginning.