Update [1/10/2020, 9:20 a.m. ET]: Capcom tells USgamer that the company is aware of the fan patch and "looking into it."
The original story follows:
Playing fighting games online is tough. You want latency similar to the feeling of playing against someone sitting next to you, but the reality can differ greatly from that ideal. One player has taken up the mantle of "fixing" Street Fighter 5's netcode on the PC, and so far, results have been positive-at least for other patch users.
A fan-modded patch for the PC version of Street Fighter 5 by user Altimor was posted to Reddit yesterday and quickly spread around the fighting game community. The idea is to fix a well-known hitch in Street Fighter 5's online play, where artificial lag and rollback can make matches really rough for players. Noticed by Mike Zaimont of Skullgirls fame years ago, this patch tries to ensure that your gameplay will never drag or pull ahead too far from your opponent's.
Concepts like rollback netcode or in-game "clocks" can seem nebulous to people who don't engage with this sort of thing. Picture yourself playing a fighting game online: Your inputs are local, and don't have to go anywhere for your screen and console to execute. But your opponent's have to be sent across the internet to your box in order for your opponent to move, and vice versa. This happens in milliseconds, but in a game where attacks and combos live in sub-second moments, too much hitching can be noticeable, whether it's a first-person shooter, rhythm game, or fighting game.
In general, online multiplayer in fighting games operates with a set amount of delay to account for this travel back and forth. But new ideas of netcode have emerged, like rollback; it's not important to dive into the granular details on that right now, though this video with Killer Instinct's Adam "Keits" Heart is a great primer on the subject. For Street Fighter 5, just keep in mind that there's a universal delay at all times of a few frames.
As players found, if one side starts to lag behind the other, they would start receiving inputs from farther into the past than they should, while the player who was behind might be receiving inputs from "the future." A schism would develop between the two, so it never feels quite right. This has been discretely documented by Zaimont and other fighting game players.
Altimor's patch reportedly addresses this by ensuring the round-trip time for the flow of information between two Street Fighter opponents never gets too far on either end, so the rollback never becomes so dynamically offset.
The incredible thing is, it seems like it's already working. Players are reporting that, when both players have the patch installed, it's making the game "a LOT more playable" even on three-bar connections.
I'll have a more in depth dive tomorrow, but here are some clips from a match I played tonight from my apartment in CALIFORNIA vs a player in SAUDI ARABIA using the new SFV PC netcode mod. Here are some highlights. It's so good. Sooo gooooood pic.twitter.com/NDSyT7QAdn- Just UltraDavid (@ultradavid) January 9, 2020
While Street Fighter 5 still experiences some "jitters," they're the kind you would normally expect from playing a fighting game online. The patch overall seems like a golden fix, with one glaring exception: those without it are starting to experience new issues playing against those who do.
Street Fighter 5 is cross-play, so now three distinct communities have emerged: PC players with and without the patch, and PlayStation 4 players. Some players are already reporting cross-play issues where PC-patched fighters can force a desynchronization with a PS4 opponent.
This has also caused a lot of hostility toward Capcom. Altimor says they took "over two days" to make this patch, while the issue has been known for years. Seeing the results, players have resulted to some aggressive calls for Capcom to universally implement the change. The sudden disparity in play, between both console and PC, and within the PC community, certainly doesn't help.
We've reached out to Capcom for comment, but did not hear back by publication.
It seems like Street Fighter 5 is in its twilight years, with a Champion Edition binding all the game's content since launch into a single package and fighter #40 on the way. This "fix" actually ends up adding a wrinkle to all of that, suddenly begging the question of whether Capcom would try to implement some form of Altimor's fix, or whether this divide will define Street Fighter 5's final moments.