73

Because when humans — and AI trained on human text — are asked to “pick a random number,” they often avoid numbers that feel too obvious like 50 or 100.

73 ends up being unusually common because:

it sounds specific and “random enough,”

it’s culturally memorable from The Big Bang Theory,

people online repeatedly mention it as a “random random number,”

and language models learn patterns from human-written data, so 73 appears more often in training examples.

So it’s not truly random in the mathematical sense. It’s more like a statistically popular fake-random choice.

If I used a real random generator, every number from 1–100 would have roughly the same chance of appearing.