SNK added a pretty awesome update for King of Fighters '98 which brought the rollback netcode and a few other additions.
Rollback netcode is a pretty big deal fighting games as it's currently the best way of handling latency for the genre. There are two main ways of going about the issue - delay-based netcode and rollback netcode.
In the case of delay-based netcode, if one player is lagging, both players will experience delay in their inputs. Once that delay has passed, all their inputs will be executed at the same time. In short, it means if one person is getting a delay, then both are, which usually brings frustration over lag when you're not supposed to be getting any.
Rollback netcode deals with the problem in a different way. Both sides look like they are executing inputs immediately but the game will go back and recalculate inputs so they properly fit the timeline. For example, if the player without or with lower latency lands a hit on the enemy, it might be recalculated after a few fractions of a second, in case the lagging player was holding the block button at the time of the attack input. Thefore, the game will go back and count the attack as blocked, even though it may have looked otherwise.
Anyway, while not perfect, rollback netcode is the top tier solution for fighting games these days so it's a pretty big deal that King of Fighters 98 is getting the feature, ensuring smoother gameplay for everyone.
The update was already live at the time of publishing so the next time you load up, you might find the online experience slightly different but improved overall.
