thoughtbot/stairs — pull request #1 by pbrisbin (2014-03-09 15:53:57+00:00)
Title: Add some test.check specs

For `new-rating`:

- Ratings should remain the same when an expected outcome occurs
- An unexpected win should improve my rating by the same amount as an
unexpected loss reduces it

For `expected-score`:

- The expectation that I'll win plus the expectation that you'll win must
always sum to 1.