Where are iTunes smart playlists stored on disk? I want to create a Best albums smart playlist containing a somewhat reasonable number of songs :   


the rule Album rating is greater than ★★★ result in a 221 songs playlist.  
wheareas the rule Album rating is greater than ★★ result in a 4000+ songs playlist.


I understand why those numbers, but still I would prefer that the resulting playlist contains ~1000 songs : hence my need to have access to the smart playlist file definition so I can overwrite the ratings representation inside.  

Other approach tried : activate half star ratings (to create a 'greater than 3.5 stars' rule), but if half star is activated for song rating in the main window, it is not the case for the smart playlist dialog.
In the smart playlist edit panel, just specify a max limit for the number of songs (eg: max 1,000 songs or max 4GB), and also choose that it should choose the highest rated songs to reach that limit.