Two pieces of gear both master worked 8/12.
Heavy hitter base value is 2. On one item heavy hitter did not crit but was doubled to 4. On the other identical item heavy hitter did crit but has the same value of 4.
These kinds of things are the reason why none of us trust the game. Blizzard math at its finest. And also more wasted mats.
To quote the one adventurer who got separated, “Is there no end?”