The chance effect in Statistics is represented by the sampling error.
When something is unsystematic, it's then due to chance. If an error is systematic, it's a bias.
The chance probability is:
- 50% for a two binary event (tossing a coin).
- 33% for a three class classification
Chance is another word for random.
Documentation / Reference
* If you’re so smart, why aren’t you rich? Turns out it’s just chance