[rangewookie]

20-30ms would be noticeable to a trained eye. Speedrunners often hit buttons frame perfect during a 1/30th or 1/60th second window. Many people today are playing on 120-240hz monitors. Additionally, if you're training on gameplay from X game and that game has theoretical ghost frames that the player doesn't see / shoot at, then the hack shouldn't shoot at it either.

It's a bit of a chicken an egg problem.

[lifeformed]

Speedrunners are anticipating the events though, and perform a remembered sequence of inputs in response to an earlier stimulus. Nobody can react to a random event within 1/60th of a second (17 milliseconds) - average human reaction time is 200-300ms. But I guess you would still visually notice a visual artifact of enemies flickering in and out of existence at 20-30ms.

[cmeacham98]

Speedrunners do that via timing, not reaction. The fastest possible human reaction time with any level of consistency is somewhere around 100-120 ms, so if you reacted to 'ghost enemies' faster than that you would be definitely cheating.