A team of computer scientists at the University of Alberta has solved the math behind checkers. Using a database comprising of all of the 500 billion billion positions (5 * 10^20), 'Chinook' has determined which 100,000 billion (10^14) are needed for their proof, and run through all relevant decision trees. They've gone and put up a site
where you can see the proof, traverse the logic, and play their unbeatable automaton.
I wonder what other games will be un-beatable in the future??