Update: Capcom has published a blog confirming what adjustments have been made to Street Fighter 5's netcode.
The short summary of the adjustment is that it "reduced the impact of one-sided rollback affecting the leading user when the connection between the two users' online match is out of sync. By doing so, the input corrections between the leading user and the subsequent user are now expected to be more smooth and accurate."
Capcom recommends that if you are experiencing issues during online matches, you should review your network setup. You can find the details of the adjustment on Capcom's site.
The original story follows:
With the launch of Street Fighter 5: Champion Edition, it seems like this generation's entry in the venerated fighting game series is nearing an end. But a recent update to the game's netcode, and the vague way in which it was announced, generated more questions than answers about Street Fighter 5's online future.
Last month, a fan-made patch addressed some long-held grievances over Street Fighter 5's netcode. While the experience was better, it also created a divide in the playerbase—those who had the PC patch benefitted, but players on PlayStation 4 and PC (without the fix) saw crossplay dissolve.
Capcom told USgamer at the time that it was aware of the fan patch and "looking into it." This would culminate in last night's netcode adjustment, announced via series producer Yoshinori Ono's Twitter.
We hope you're enjoying #SFVCE and thank you for all the support!A netcode adjustment has been made to the game and is available now for all players.We ask that you send your feedback to @SFVServer. Please enjoy and look forward to #CPT2020 #SFL2020 #IntelWorldOpen starting soon! pic.twitter.com/r6DirOrqUn- Yoshinori Ono (@Yoshi_OnoChin) February 19, 2020
There was a noticeable lack of patch notes or details as to what this entailed, beyond "a netcode adjustment has been made to the game." We've reached out to Capcom to get details of what the patch entailed, but did not hear comment by publication.
In lieu of official word, the community has relied mostly on anecdotal evidence and dissecting code to uncover what was actually changed. For a good few hours, this meant any level-headed discussion often being met with vitriol.
As Twitter users like ToolAssisted have discovered, the netcode adjustment seems to do something similar to Altimor's patch, though reports vary from person to person on how effective Capcom's fix is. Ono's original tweet solicits that you reach out to the dedicated SF5 Server account with feedback.
The short version of what this netcode does is adjust the maximum amount of time the two game states can spend de-synchronized from one another. Because playing a fighting game online requires two simulated states be kept up-to-date with one another, if the information moving between the two gets slower than the game itself moves, the netcode needs to adjust.
This issue is why rollback netcode has become so popular. And while it seems like Capcom's fix is at least a step in the right direction, the lack of clarity and the eagerness of some players to jump on any misstep can lead to a lot of confusion over what's being fixed, and how. For a short while last night, some users even assumed that the only adjustment was deleting the fan patch like it never happened, and it took others digging into the update to prove that wasn't the case.
Time will tell if this update ends up fixing one of Street Fighter 5's longest-running issues. In the meantime, you can check out what Reviews Editor Mike Williams and I thought of Street Fighter 5, both the good and bad, in a roundtable discussion on the Champion Edition.