1% crit/mastery = 1% chaos bolt damage.
600 crit rating per 1%
200 mastery rating per 1%
They only factor mastery into the tooltip, so you won't see it change if you alter your crit, and its also why the tooltip doesn't match the actual damage (plus the 3% crit meta, the fact that it crits means its 2x damage, and the 5% spell debuff if you have it.)
( ( 2.25 * my spell power ) + 2164 ) * 2 * 1.03 * 1.05 * crit percent * mastery percent = chaos bolt damage. 2x multiplier from it critting, 1.03 from the 3% crit damage meta, 1.05 from the 5% spell power debuff.