Performing a memorized action isn’t the same as reacting.
Reaction time is how fast you can *react* to something, *when you don’t know when it’s coming*. But like, look at anyone playing piano or guitar – are they limited to one one note played every 0.2 seconds? No way! That’s only 5 notes per second. Heck, I bet you can click your mouse or tap your phone screen much faster than 5 per second right now!
That proves that “reaction time” is not the same thing as “movement speed limit”. Speedrunners aren’t actually *reacting* to the screen, they’re doing something much more like a piano player playing a fast song *that they already have memorized*. If the game was altered to have one extra obstacle the speedrunner didn’t know about, there’s no way they could react in time. They’d just die.
Latest Answers