Think Lisp is a dead language? Not according to Gábor Melis, who was just crowned the winner of the PlanetWars Google AI challenge. His bot "bocsimacko" dominated a field of over 4600 contestants, but was one of only 33 programmed in Lisp.
Bocsimacko debuted in the official contest ratings on October 22nd. Two days later, it was in the top spot and never looked back. The contest quickly became a race for second place. After seeing Gábor's performance, many participants commented that they would be taking a new look at the 50 year old language. "Bocsimako is the proof that Lisp is best for AI algorithms," quipped one player. "I'll have to learn more Lisp just to understand your code," said another, after Melis uploaded his source code at the contest's end. If you speak Lisp, you can view it online here.
When asked about his language choice, Gábor responded "I'm thankful to have been programming in Lisp professionally for 6 years." He says he tried Java but found it "incredibly boring":
Lisp doesn't get in my way as much as other languages. After getting hooked I learned to value the interactive development environment, the object system, etc.. What's good about Lisp is rapid development and speedy execution.
So why don't more people use Lisp?
Syntax is what puts people off. When confronted by something new, we look for a reason to discard it. Syntax happens to be this reason for a lot of people without realizing why it is so.
Gábor is no stranger to the field of computerized competition, having taken home a gold medal at the Computer Games Olympiad in 2003, 2004, and 2006. As a senior developer for the privately held firm RavenPack he created algorithms to parse news feeds and create models for stock trading programs. Nowadays he works for Franz Inc., a Lisp company.
PlanetWars is the 4th AI contest sponsored by the University of Waterloo Computer Science Club and the 2nd to be co-sponsored by Google. The first contest was called Minesweeper Flags, followed by Rock Paper Scissors, and then Tron. (Yes, they actually had a contest writing programs to play Rock Paper Scissors. "RPS is harder than you think," says contest organizer Jeff Cameron. "It's not random. It was iterated RPS.") Planning is already underway for the next event but the game has not been decided.
The PlanetWars contest received extra attention due to a post on reddit titled "The end is near! Self-improving AI based on Genetic Programming is beating 95% of hand-coded submissions in the Google AI Challenge". The genetic algorithm coded by a team calling itself space.invaders did better than expected but ended up in 277th place.
Machine learning algorithms like that one were a constant subject of discussion on the online forums, but none of the top bots are believed to have used the techniques. One contestant posed the question, "Does your bot learn?" to leader Melis. "No," he replied, "I do."