Introduction: Foreword by Mark D. Rejhon

Blur Busters writes about “Better Than 60Hz” monitors, including our ongoing 480 Hz monitor tests, and we have the 240 Hz GSYNC Input lag Tests. These all push bleeding edge limits of reducing input lag.

Now we visit the human portion of input lag.

Humans take time to react; whether to the starting pistol of a Olympics 100 meter sprint, or an enemy in an online match of Counter Strike: Global Offensive. The best players in the $1-billion-dollar eSports industry push the limits of human reflex, and apparently surprisingly so.

Many studies have been on Olympics sprint race reaction times, but few studies exist with reaction times in high-end competitive gaming that involve champion players.

Introducing Marwan Daar

We got a researcher, Marwan Daar, to do some preliminary research on this topic. Marwan Daar, of York University (Toronto, Canada), has written several vision research papers (ResearchGate profile) and participates in many online discussion forums under the nickname spacediver, so readers may be familiar with him.

He has written a special article for Blur Busters on human reflex. Needless to say, some data points are eye-opening, with apparent sub-100-millisecond results that certainly merit further detailed study.

Begin reading Marwan Daar’s article: Input Lag and the Limits of Human Reflex, Part 1

4 Comments For “Input Lag and the Limits of Human Reflex”

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Great work and interesting article. I have a few criticisms and some insight:

For the most part you only stress reaction time in relation to input lag, but perception and cognition is also extremely important. From taking the A/B input lag test someone made on the forums here, myself and a friend were able to pass the test down to recognizing a 5ms difference. From playing games with varying levels of input lag it is clear that just feeling a small amount of input lag despite a consistently high fps plays a major factor in coordination.

Regarding your tests, I play at a similar level so I can offer some additional input. I agree that oftentimes this type of aim isn’t conscious. Pattern recognition definitely plays a part. There’s a phenomenon amongst pro play in quake and many other fps games that sometimes standing still is the best dodge to make in certain situations because it’s the least predictable. I look like the end of frag4 is prediction based on the charts and opponent’s movement pattern. It’s worth noting that dodging is also reaction based and you may have been subconsciously trying to move the opposite way of his beam (tough with latency) and forced into a pattern. It might be worth blinding the dodger if you don’t completely randomize it or getting someone skilled at dodging. The fact that dodging is a skill of varying degrees even amongst pros points towards patterns playing a major role as well. I’d say that movement patterns with aiming usually work in that a movement can be highly anticipated, but still reacted upon instead of proactively aiming.

One thing to note is the LG has a knockback effect that is used to control the opponent’s movement to your advantage, but I think that can be disabled in custom game settings. I’m not sure if you did that. You’re correct to note the inertia of movement plays a role, but also notice that player animations clue in the shooter of the intended direction change. I think your method of accounting for the moment deceleration starts isn’t affected by that though.

It’s also worth noting that a player’s mouse movement may intentionally not follow the opponent. Take for example a player strafing to the right of your screen, ideally you want to track the left side of their body, so when they switch directions you don’t have to move your mouse much if at all (and they’re walking into your knockback) while you see if they’re going to continue their direction change or go back in their original direction.

I hope some of this helps, and again, really interesting article.