Riot is on a crusade to eradicate 'peeker's advantage' in its new FPS Valorant

How many truly universal experiences are there in human existence? The love of food; the joy of a truly cute puppy pic; exclaiming "that's bullshit!" when a bullet in an online shooter somehow kills you through a wall. If Riot Games engineer David Straily has his way, that experience will not extend to Valorant, Riot's upcoming tactical shooter. When I played several hours of Valorant in January and talked to Riot's developers, I was surprised that they weren't talking about bold, new ideas that would make their shooter unlike anything else on PC.

Instead, they were talking about the less-sexy technical stuff: anti-cheat, netcode, and a desire to eliminate peeker's advantage altogether—things that could draw in competitive players frustrated by cheating or lag in other games.

Unlike a lot of the complicated code that goes into making online games work, peeker's advantage is "something you can actually visibly see and tell," Straily says. 

The short explanation of peeker's advantage is that, due to the travel time of data packets over the internet between players and game servers, the aggressive, moving player usually has the advantage. One player peeking around a corner can move back to safety before their opponent has time to react, or the server even registers their movement. Peeker's advantage inherently rewards aggressive play because the defending player will always be reacting on a delay.

"A lot of players in CS:GO do jiggle peeking, where you'll rapidly jump in and out of cover as you go. That's kind of always putting you in the state of peeker's advantage because you're always popping out ahead of them," Straily explains. "That is a way to play the game, and you have to generate unique skills as a player. You subconsciously internalize the state of networking. Maybe you don't realize that as a normal player, but you are doing that. We can appreciate seeing people enjoy playing that way, but what we want to do on Valorant is make it more natural, a little more like real life situations… we think this is going to provide a better affordance for deep gameplay. It's simply more strategic if you have to think about going around a corner by using a utility or ability from one of your characters. You have to be thinking more critically, and we want it to be more of a thinking man's game."

As the victim of peeker's advantage, you might not see your opponent until their bullets have already landed

So how is Riot trying to address peeker's advantage in Valorant? It helps to have a firm understanding of what actually causes peeker's advantage at a technical level. Rainbow Six Siege's developers wrote a great blog explaining why peeker's advantage happens, including a helpful animation. Here's the short version: 

"Replication is the process by which we mirror a sequence of movements and actions done by a player on a remote computer, such as a game server. You can think of replication as 'ghosts' that follow players. This 'ghost' represents your position as seen by the server. For example, if you have a ping of 200ms, your 'ghost' is where you were 100ms ago (since ping represents round trip duration). The higher a player’s ping, the further behind the player their 'ghost' is...

"Peeker’s advantage is a result of the aforementioned 'ghosting' effect. We cannot remove 'ghosting': doing so would require all movements to be validated by the server before taking effect on your client. This would result in increased input delay (equal to your ping), which is contrary to the design philosophy of making movement as reactive as possible. However, unlike the common perception, peeker’s advantage depends only on the speed of the victim’s connection, not the peeker’s.

"The maximum time, once the peeker becomes visible, that the victim has in order to shoot and come out on top is what we define as the window of opportunity. Peeker’s advantage is caused by the fact that this window of opportunity is always shorter than the reaction time of the peeker."

The key weapon in Riot's attack on peeker's advantage is Riot Direct, a private infrastructure for League of Legends. Riot placed routers at major internet traffic hubs in 35 countries, then made deals with internet carriers to connect their network to the wider internet. The end result is that packets get to players with far fewer hops, in many cases dramatically lowering ping.

Ping is a crucial aspect of peeker's advantage. Remember, the amount of time it takes the peeking player to tell the server "I am here," and for the server to relay that information to the affected player, determines the window of opportunity they have to react.

According to Straily, in testing Valorant with pro players they found that 80 milliseconds feels like a "fair" window of opportunity—it's fast enough for players to react, keeping peeker's advantage at a minimum. But his team has beaten that, getting the windows down to only 60 ms.

Efficient connections between players and servers make that possible. Thanks to Riot Direct, most players will be able to reach Riot's servers with 60 ms ping or less. Straily estimates that at launch, that number will be only 35 ms for 70 percent of players.

Another major factor is that Valorant runs entirely on 128 tick dedicated servers, which means the server is updating the game state 128 times per second and sending that information to all 10 players in the match. That's every 7.8 milliseconds. The combination of low ping (data being sent across the internet more quickly) and high tick rate (the game server updating clients more quickly) is powerful. The end result, for your eyeballs, is a tiny delay between what you see on your monitor and what's currently happening on the server. You'll have a fairer chance to react, and odds are your human reflexes will be the reason you die when someone pops around a corner, not how long it took the packet to reach you.

"We don't want to be secret about the technology… because we want to kind of raise the bar for everyone," Straily says. "It's great that we're doing 128 tick for free for everybody, but we don't want to stay there above [the competition]. We want everyone to kind of raise the level so that the bar is always raising, so that everyone can have a better experience as time goes on."

I asked Straily if there was anything he wanted to evangelize to players about netcode, given how complex a topic it can be. After talking about peeker's advantage, he brought up the one aspect of the online experience that Riot can't control: Your computer.

"There's so much technology around us in the world, a lot of times people take for granted the setup that they've been given, whether it be their router or their internet," he says. "We want you to understand how your computer's acting, how your router's acting, how your internet is acting, how game servers are acting.

Valorant's developers have built things into the game to help players understand those things, like screen indicators for packet loss. Straily says they're making an effort to help players understand if their problem is their PC delivering a low framerate, or the servers are having problems, or if there's some other random network issue.

"We want to give you those tools so that you can educate yourself so you can understand, hey, I don't have to deal with a substandard form of gameplay. I can see what's going on. I can go fix it. I can go buy a better machine. I can go buy a better router and bring myself up to where I really want to be."