Shuffle records and round robin

[Jon]

I am running BIND 9.2.2.  Recently I have been looking into using
round robin to split the traffic over a few servers.  As far as I can
see, its quite straight forward, just a case of entering each IP for
the host.

www IN A x.x.x.x
www IN A z.z.z.z

The question is a "how do they do it".  I notice yahoo.com returns a
number of IP addresses, so that can't be using round robin, as I
thought that only returns 1 IP (from the ones you entered).

bbc.co.uk only gives out one IP and if you wait for the TTL to expiry
and query again, normally you get a different one - this I believe is
round robin in action.

Is the method yahoo.com use shuffle records, where it trys to order
the IP addresses in an order which is closer to me (well the IP I am
querying from).  Is the rrset-order option?

Graeme