Shuffle play - can I "force" iTunes to play an un-played track

Question

I've got just over 6000 tunes on my iTunes ... that's not meant to be boastful, just a way of putting what comes next into context.
When running iTunes on random shuffle play it seems to have a knack of re-playing one of the thousand-or-so tracks that have been played already out of the library already instead of selecting something new. This seems to be happening sufficiently often that I am beginning to suspect it's not coincidence. I am not aware I have any Genius functions or similar running ... well I haven't set them up (nor am I aware I am paranoid!).
Is there any way of "encouraging" iTunes to play something different? Fairly frequently the re-played track is not just something that's been played before but is something I only heard a couple of days ago which is why I started to notice this was happening.
It suggests there's something going on in the track selection algorithm. Can I instruct iTunes to "algo-playsomethingdifferentrhythmsforachange"?

Answer 1

Start with File > New Smart Playlist
Edit the initial rule by changing the drop down lists and adding values where appropriate.
Use the + or - buttons to add or remove rules.
Use Match all or Match any to control how multiple rules interact.
The ellipsis ... lets you create more complex rules without requiring supplemental playlists, E.g. (A OR B) AND (C OR D) where A,B,C & D are different rules that match a subset of the library.
tt2