: Google's "Information retrieval based on historical data" patent is about as close to authoritative (i.e. not anecdotal) data as you can get: [0101] Also, or alternatively, the age, or

Google's "Information retrieval based on historical data" patent is about as close to authoritative (i.e. not anecdotal) data as you can get:

[0101] Also, or alternatively, the
age, or other information, regarding a
name server associated with a domain
may be used to predict the legitimacy
of the domain. A "good" name server
may have a mix of different domains
from different registrars and have a
history of hosting those domains,
while a "bad" name server might host
mainly pornography or doorway domains,
domains with commercial words (a
common indicator of spam), or
primarily bulk domains from a single
registrar, or might be brand new. The
newness of a name server might not
automatically be a negative factor in
determining the legitimacy of the
associated domain, but in combination
with other factors, such as ones
described herein, it could be.

This would suggest that the domain's registration data and nameservers do factor in, however, anecdotally, (nameserver changes, registrant info changes, registrar changes) I would say that changing registrars has very little long-term impact on a domain's ranking.