In the code of XCOM2, modders have discovered that the game cheat in your favor by increasing your chance to hit if you've missed in your lasts shots. And lower the chance of the enemy hitting you if they've already hit you this turn.

So you can (and will) miss 90% shots, it should not happen twice in a row the same turn.

Edit : Found the source : https://twitter.com/m1sp/status/697268847187890176