I think a good way to look at it is:
There is effectively a spread on all hitscan weapons, due to the fact, that the exact moment that you are clicking, is not actually the moment the shot is fired. As demonstrated in the video with only white lines, if a shot was fired at any point between the white lines, the shot would actually have been fired at the white line.
In effect, this means that while you’re playing there is effectively a 16ms’ worth of mouse movement’s inaccuracy to your shot. So if you are flicking and shooting as mccree, and hit the enemy widowmaker perfectly in the head, but are unlucky with the polling time, you shot might actually be launched 16ms later, at which point your aim might not be exactly on the Widowmakers head anymore.
To make an exact example:
Lets assume that you make a 45degree flick on mccree in 240 seconds (looks like thats what’s approximately in the video above). Assuming that you can’t perfectly stop the mouse at your target (which you cant because you are human), this will effectively mean that there will be an inaccuracy to your shot of 3 degrees with the old system. With the new system and a polling rate of 1000, the inaccuracy will only be 0.1875 degrees. If you are shooting at a target 20 meters away, on the old system this would mean an inaccuracy of 1.05 meters, and on the new system an inaccuracy of 0.07 meters.
Effectively this will be an advantage
Players who enable this option (assuming that they have a mouse supporting the higher polling rate), will decrease their inaccuracy by a small margin. For low skill players who have a high inaccuracy simply because their aim is bad, this will represent a tiny part of their inaccuracy, and not have a large impact. For high skill players who have inhumanly good aim, this inaccuracy reduction will represent a relatively large part of their remaining inaccuracy, and it will be an accordingly large ‘buff’. It’s not a must have mechanic to stay competitive, just like high framerate isn’t technically a must have to stay competitive. Players have reached top500 with 30fps, and they certainly will also with a polling rate of 62.5hz.
This will mostly affect playstyles that rely on large flicks. Some players flick a lot when playing snipers, and some rely more on tracking. The flickers will experience the largest impact. This is true across all heroes. Genji players that play up close a lot for example, will likely also experience more “why did that not hit” moments.
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