i assume when your trying to score one that hes decent.
i imagine holding a tine with my hand with my thumb up ( like the fonz)from bottom of the tine totowards the top.this is almost 7 inches on my hand. using that i try to quick score whats pointin up.
ex g1- say 8in g2 say 7in g3 say 4in, brow - 3in= 22inchs ,
if hes almost symetrical ---double that------44 inchs if there something extra on one side quickly add that or subtract if its missing.
then look at overall rack, if hes a decent buck , i will score as follows
add for
ex wide& thick --120 inches------------so above points will score164
ex wide or ex thick --110 inches-------------------------will score154
avg width and thickness--100 inches---------------------will score144
no width or skinny-- 90 inches----------------------will score 134

so add the inches of points sticking up then add overall rack size and you got a approx.quick score when i first started doing this i would quick score every rack i seen then get actual score and have gotten where its pretty accurate for gross scoring.