Improving accuracy of myself here: duodecimal beats decimal because 12 is a highly composite number (i.e. it has more dividers (1, 2, 3, 4, 6, & 12) than any smaller integer). 6 is higly composite too (having 4 dividers, being as good as 10 in that regard), but 20 isn't (having 6 dividers, being...