Here is a quick hash I came up with (original mix smartlist adapted from the big smartlist thread a while back). Any thoughts or suggestions on improving?
I wanted to guarantee a certain number of Christmas tracks ended up in the mix, but since they are a minority of my music I figured I had to hard code that to make it work. The two lines that are grouped together are identical except for number of tracks and genre. 200 tracks usually works out to 13-15 hours of music.
~mix=200,
25,{-[Genre]=[Christmas] Rating=>=4 ~sort=[number plays],[Last Played]-d,[date imported]-d ~%=50 ~sort=[random]},
5,{[Genre]=[Christmas] Rating=>=4 ~sort=[number plays],[Last Played]-d,[date imported]-d ~%=50 ~sort=[random]},
15,{-[Genre]=[Christmas] Rating=>=4 ~sort=[number plays]-d,[Last Played],[date imported] ~%=50 ~sort=[random]},
5,{[Genre]=[Christmas] Rating=>=4 ~sort=[number plays]-d,[Last Played],[date imported] ~%=50 ~sort=[random]},
71,{-[Genre]=[Christmas] Rating=3 ~sort=[number plays],[Last Played]-d,[date imported]-d ~%=50 ~sort=[random]},
15,{[Genre]=[Christmas] Rating=3 ~sort=[number plays],[Last Played]-d,[date imported]-d ~%=50 ~sort=[random]},
34,{-[Genre]=[Christmas] Rating=3 ~sort=[number plays]-d,[Last Played],[date imported] ~%=50 ~sort=[random]},
10,{[Genre]=[Christmas] Rating=3 ~sort=[number plays]-d,[Last Played],[date imported] ~%=50 ~sort=[random]},
11,{-[Genre]=[Christmas] Rating=2 ~sort=[number plays],[Last Played]-d,[date imported]-d ~%=50 ~sort=[random]},
3,{[Genre]=[Christmas] Rating=2 ~sort=[number plays],[Last Played]-d,[date imported]-d ~%=50 ~sort=[random]},
4,{-[Genre]=[Christmas] Rating=2 ~sort=[number plays]-d,[Last Played],[date imported] ~%=50 ~sort=[random]},
2,{[Genre]=[Christmas] Rating=2 ~sort=[number plays]-d,[Last Played],[date imported] ~%=50 ~sort=[random]}
~sort=[random]