How Overwatch servers handle client mouse inputs, and why you should enable High Precision Mouse Input

I just saw Overwatch gameplay engineer Derek Mulder’s reply to his post on the then newly added High Precision Mouse Input option. It was buried deep in that thread and I thought it would be helpful to post about it here. Most who saw the initial post would have probably missed that reply (I know I did). Hope this is helpful.

tl;dr If your mouse has a polling rate of 1000 Hz and you enable High Precision Mouse Input, you can (sort of) think of your flick shots as if they are being calculated on a 1000-tick server.

Slightly longer tl;dr Overwatch receives mouse inputs from clients 62.5 times per second for the purpose of hit detection. With High Precision Mouse Input on, while the tick rate is still 62.5 Hz, when a server receives an input containing a discrete primary/secondary fire (so not holding down the fire button), instead of resolving it in a game state at that exact tick, it “rewinds” and calculates hit detection in a game state (which I assume is interpolated) somewhere between that tick and the previous tick. What this means is, peeker’s advantage notwithstanding, with High Precision Mouse Input enabled the frequency at which Overwatch (sort of, due to interpolation) calculates hit detection for discrete primary/secondary fire is the same as your mouse’s polling rate.