We gave it a B+
Subject: The Unfinished Game by Keith Devlin suggests that the concept of probability sprang from a correspondence between two brilliant French mathematicians in the summer of 1654.
Observations: The science of chance and likelihood was ? a huge intellectual leap that put to rest the prevailing notion that a divine hand was ruling human lives.
Conclusion: Challenging (for me) yet surprisingly engaging.
Science Level: Likelihood that you’ll need to be familiar with advanced math: high. B+