It's been over a quarter of a century since Capcom released Street Fighter II: The World Warrior into arcades in 1991, but the game's enduring legacy still drives devs to pick it apart in order to figure out how it works. 

At least one of them has a whole blog dedicated to the project of reverse-engineering Street Fighter II's source code, and earlier this year that blog published something fellow devs may get a kick out of: a detailed breakdown of how the game's AI works.

The post is less about useful takeaways ("anyone looking for some insight into how to write an AI engine for a game today will be disappointed") and more about answering some pressing questions about how Street Fighter II AI opponents tick.

For example, the author acknowledges that SFII AI cheats in multiple ways: it can execute charged special moves with zero chance of input failure, and it has a frame advantage on a human player because it can immediately see what move a player has input, before the move's opening frame.  

For more on how the AI works, including a breakdown of the scripting that dictates say, when Ryu throw fireballs and how many, check out the full post over on the SF2 Platinum blog.