New ask Hacker News story: Ask HN: What are some good unintuitive statistics problems?

Ask HN: What are some good unintuitive statistics problems?
3 by ronbenton | 2 comments on Hacker News.
I am compiling some statistics problems that are interesting due to their unintuitive nature. some basic/well known examples are the monty hall problem and the birthday problem. What are some others I should add to my list? thank you!