Google's John Muller said in a webmaster hangout on Friday that GoogleBot will follow up to five redirects at the same time, past that, you are probably out of luck.
I don't believe we had a number, a solid number, on how many redirects Google will follow. This may, and I may be wrong, be the first time Google gave a number on the number of redirects they follow at one time.
We had Matt Cutts talk about PageRank dilution through redirects in the past.
Google's John Mueller said this 46 minutes and 3 seconds into the hangout embedded below:
Of course, this is useful information for SEOs when doing audits.