Rooster, other factors simply mean, when considering for example teams off 230/100-100 games (see my stickied thread in this forum), where a/each team is regarding offense in recent games (coming off a long sequence of high scoring games where its perceived they're headed for a lull, or the opposite), what their scheduling situation is (3rd in 4? B2B?, 4th in 5?), etc. Its simply all the various aspects influencing the contest, not just the 230/100-100 situation alone.
My problems with systems is they inevitably require reducing all aspects involved - or that are being considered - to numbers. Some of those numbers are pure (ie, taken from stats derived directly from the teams involved) which is fine, but then other non-numerical factors have to be assigned a numerical weight (scheduling, opponent strength - they shoot better against weaker teams, worst vs better teams, ad infinitum - injuries) because ultimately systems are really glorified equations. You enter all your numbers into a "pot" then you "brew a soup". I simply dont see anyone getting those non numerical factors all weighted correctly to the stage (inside or outside of a specific math equation) where their system will work to the degree necessary.
Thats why to me they always fail. Either they havent got the complexity (number of factors being considered) required in the first place, and/or the non-numerical factors arent correctly weighted.
It just screams of too much work, and too much time when - dare I say it - there are easier ways.