I need some help getting started with a program I'd like to write. My question has little to do directly with Perl, (aside from the fact that I'll be using Perl to write the program) but I hope you'll find the question interesting and permit me this small indulgence.

I'd like to write a program that will play Rock-Paper-Scissors with the user. Simple enough on its own, but I'd also like it to, over the course of several games, watch for patterns in the user's choices and try to guess what they'll pick next. Similar to the AI board games that get better each time you play them, but on a smaller scale.

My question is, how would you approach the problem? I've never written anything like this before, and I don't really know where to begin. Any information would be greatly appreciated.