Have you ever plopped a quarter in the Street Fighter II machine at your local pizza joint and readied up with your favourite character, only to find yourself bashed and bloodied by the CPU just a few rounds later? Perhaps you said something to yourself about the computer cheating, only to get heckled by your friends. Well, according to this YouTube video, it totally was.
These underhanded tactics include becoming completely invincible for short periods of time, which allows them to interrupt attacks that are normally safe. Desk demonstrates this with side-by-side footage of the same situation being played against the CPU and a human to show just how devious the arcade mode opponents can be.
Let’s say you manage to hit the CPU with enough attacks to stun it. Time for free damage, right? Wrong. Street Fighter II allows CPU opponents to escape the dizzy state in just 12 frames, or 1/5 of a second at 60 frames per second.
This is incredibly fast and, to the best of my knowledge, it’s a speed that’s impossible for a human to pull off even with optimal execution. In effect, it’s a little like the rubber-banding tactics seen on the part of AI opponents in games like Mario Kart.
The last bit of Desk’s video covers how the CPU can perform charge and mashing moves — like Guile’s Flash Kick and Chun-Li’s Lightning Legs, respectively — without the requisite inputs. This means Guile can simply walk forward and Flash Kick whenever he wants, forgoing the down charge necessary to pull off the move as a human. Sometimes, the CPU even fakes like it’s charging to give the impression that it’s totally above board.
Much of the info cited in this video comes courtesy of blogger sf2platinum, who has spent years digging through the Street Fighter II code. One post in particular details the AI engine, explaining the game’s unsophisticated methods of turning the CPU into a decent sparring opponent. Give that a look in between frustrating rounds of getting screwed out of your quarters.