# ./ tools / probability

### virtual dice

### virtual coin

### odds to probability converter

### scientific betting

the kelly strategy for placing bets tells you the optimal amount to invest given some known probabilities.

### pigeonhole principle

the pigeonhole principle leads to some surprising unintuitive results. e.g. you only need 23 people in the same room for it to be more likely than not that 2 people share a birthday^{[1]}