system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: how come we have computers that can beat chess champions since 1996. but now in 2014 video games AI are still horrible ?
gpt
Researchers have studied chess for decades.  Chess, for all it's complexity, has a very well defined set of moves that can be made & options for actions.

The guy writing the AI for the new Halo is an overworked dev who would rather be doing something else & has deadlines to meet.  He doesn't have a PhD in AI or access to decades of research on optimal strategies.  On top of that, he has to keep his AI running in real-time without sucking up all the resources on a system.