In December 2020, I ran a pseudorandomness contest. Here’s how it worked:

• In Round 1, participants were invited to submit 150-bit strings of their own devising. They had 10 minutes to write down their string while using nothing but their own minds. I received 62 submissions.

• I then used a computer to generate 62 random 150-bit strings, and put all 124 strings in a random order. In Round 2, participants had to figure out which strings were human-generated and which were “truly” random. In particular, I asked for probabilities that each string was real, so participants could express their confidence rather than guessing “real” or “fake” for each string. I received 27 submissions for Round 2.

The analysis post (the last in the series) may be interesting to you even if you did not participate in the contest!