[justinrstout]

In fighting games we still have to worry about _network_ latency, as high ping will cause frequent rollbacks. A more accurate way to think about it is that rollback netcode enables very low _input_ latency which makes online feel more like offline, compared to previous implementations that literally delayed controller input while playing online.

Humans cannot react to anything in 20ms, it's closer to 200ms. We consider a move faster than about 18 frames to be effectively unreactable in the heat of gameplay. At 60 FPS that is 300ms.

[interroboink]

This depends on the game, a bit. I believe you are talking about reacting to unplanned events. For some games, such as beat-matching ones, where players might have patterns memorized, smaller latencies matter. I remember working on PS game, where Sony requested that we poll input faster than our 60Hz refresh rate so we could apply special "super accurate" bonuses for players that could hit things within such tiny thresholds.

Apparently in Japan where such games are especially popular (or were at the time), players really do appreciate such razor-thin input timing margins.