Bhags, mmmmm, yes I see where you are comming from, kinda look for the fav where,

(1) hasn't run within 21 days
(2) more than 9 runners
(3) last run WASN'T metro
(4) hasn't got a win in exposed form
(5) place % is LESS than 50%
(6) Rating is LESS than 97
(7) Carrying MORE than 60Kg's
(8) Ridden by a 3kg's apprentice (or more)
(9) Running in a race of 2000m or more
(10) If in a race of 1200 metres or less and is NOT first up!
(11) was NOT within 3.5 lenghts from the winner last start.
(12) IS NOT racing within 3.5 kg's of set weight last start (ignoring all claims)

or maybe say, if it qualifies in say 6 of the above then do the tri???