43bea4d7706b46cb8e14b7c5c4053aa4
According to the link above, the default hit calculation is 9% + 19% = 28%.
Mr Robot is currently counting at 27.4%.
Which one is correct?
28% is the cap. The optimizer tries to get you close to that without going over - any amount over would be wasted stats.
Remember that you will always have some attacks avoided (dodge) regardless of how much hit you have. In-game, you won’t feel a difference between 27.4% and 28.0% hit chance.