There seem to be multiple oddities with calculating accuracies for different weapons:
-Shotgun and Crylink apparently have acc calculated for every single pellet fired, so you can have less than 100% acc after a single shot fired (that hit), and you can even lower your accuracy with hits. No other game, that I know of, did it like that, so now numbers are pretty misleading.
-Sometimes I got less than 100% (anywhere from 60 to 90%) after a single hit from a weapon NOT firing pellets (like mortar, nex, electro or rockets), which can't even be explained as above. Also, detonation of rocket mid-air lowered my acc a few times (checked that), even if enemy WAS hit.
-Hagar's secondary can quickly rise to 100% even with some missed shots previously, and even more oddly, it doesn't fall down for a while with a few consecutive missed shots (and certainly not because there were so many of them fired)
-Hitting turrets/vehicles and assault objects is not accounted in a number. Hitting assault object doesn't even produce a hit indicator sound.
-[HARD] taking into account electro combos somehow. Given many possibilities to use combo, this is very complicated.
-Shotgun and Crylink apparently have acc calculated for every single pellet fired, so you can have less than 100% acc after a single shot fired (that hit), and you can even lower your accuracy with hits. No other game, that I know of, did it like that, so now numbers are pretty misleading.
-Sometimes I got less than 100% (anywhere from 60 to 90%) after a single hit from a weapon NOT firing pellets (like mortar, nex, electro or rockets), which can't even be explained as above. Also, detonation of rocket mid-air lowered my acc a few times (checked that), even if enemy WAS hit.
-Hagar's secondary can quickly rise to 100% even with some missed shots previously, and even more oddly, it doesn't fall down for a while with a few consecutive missed shots (and certainly not because there were so many of them fired)
-Hitting turrets/vehicles and assault objects is not accounted in a number. Hitting assault object doesn't even produce a hit indicator sound.
-[HARD] taking into account electro combos somehow. Given many possibilities to use combo, this is very complicated.


). I'm not entirely sure but iirc calculating accuracy in left4dead works like that too.