When Garry Kasparov sat down to play the IBM Deep Blue computer the Russian chess grandmaster believed he had discovered a strategy to turn the machine’s greatest strength into a weakness.
Deep Blue relied on being able to compute a vast database containing hundreds of thousands of chess games played by past grandmasters, meaning Kasparov was not simply playing one supercomputer but in fact taking on the amassed knowledge of many of the strongest players from history all at once.
But to be able to make use of large parts of its database, Deep Blue required its opponent to play like a typical grandmaster. If Kasparov was to intentionally make a bizarre opening play rarely seen in high level games the computer would have vast parts of its database rendered useless, as it would have fewer games to reference, and the human could regain the upper hand.