Shannon's 1953 Machine Beat Humans at Matching Pennies — and It Still Wins
The Aaronson Oracle
In the early 1950s, David Hagelbarger and Claude Shannon built relay machines to play matching pennies. Shannon's simpler machine, which tracked your patterns, beat Hagelbarger's more elaborate one 55.8 to 44.2 in a 2020 software replication. On the MIT Museum exhibit, the machine won 59% of the time against all human players, with a lifetime score of 5010 to 3507. Scott Aaronson later recreated it for a Berkeley class, and even he couldn't beat his own program while knowing its source code.
The machine is not unbeatable. It is beatable three times out of four, on paper. You simply cannot run the method in your head while playing.