Note that the most common 8-die roll is against DX plus ST to jump a megahex (page 104). So an IQ 8 human (or IQ 10 with Acrobatics) maxes out their jumping potential after adding 3 points to either ST or DX.
Olympic class jumpers just take four levels of Acrobatics?
http://www.hcobb.com/tft/new_spells.html#Talents